Note: Descriptions are shown in the official language in which they were submitted.
HYDRO-FURNACES AND RELATED METHODS
FOR VEHICLES
Field of Art
The disclosed invention generally relates to a heating system and is more
specifically
directed to a heating system providing heated water and air and related
methods for use in
recreational vehicles (RVs) or utility vehicles and boats. Utility vehicles
can include ambulances,
fire trucks, and military vehicles where hot water and hot air is required for
certain procedures.
Background
Conventional water heaters and furnaces designed for the home or commercial
buildings
are typically separate components, which are bulky, heavy, and require special
mounting fixtures
and safety devices. For these reasons, such conventional water heaters and
furnaces for the home
are not portable and not suitable for use in or on mobile vehicles, such as
recreational vehicles
(RVs), and boats.
Because space and weight are at a premium in recreational vehicles and boats,
hot water
heaters utilizing large tanks and furnace systems are undesirable, but
nonetheless are today
universally used, notwithstanding their weight and bulky configuration. A
typical tank-based
water heater unit includes a burner and a tank with capacity that provides 5
to 10 gallons of hot
water with recovery times ranging from 30 to 60 minutes. A typical forced air
furnace with a
separate burner and blower assembly also adds additional weight and occupies
additional space.
Hot water heaters such as described in U.S. Pat. No. 5,039,007, which provide
for both
hot water and heated air for space heating purposes, have never been developed
commercially.
Currently most tankless water heaters and water heaters with tanks designed
for recreational
vehicles and boats on the US market are limited in market share due to high
cost and poor
performance, among others.
Summary
Aspects of the invention relate to a water heater and furnace system for a
recreational
vehicle (RV) having a housing comprising a plurality of panels defining an
interior; a water inlet
for receiving water from a water supply accessible through the housing; a
system hot water outlet
accessible through the housing; a heat exchanger inside of the housing for
heating water flowing
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through the heat exchanger; a burner inside of the housing to provide heat to
the heat exchanger
to heat the water flowing through the heat exchanger; a heater core coupled
downstream of a hot
water outlet of the heat exchanger; a blower for moving air across the heater
core and delivering
heated air outside the housing; a storage tank for storing water passed
through the heater core;
and a pump circulating water from the storage tank to the heat exchanger,
wherein said water
heater and furnace system is configured to permit concurrent delivery of
heated air outside the
housing and heated water to the system hot water outlet.
Some embodiments of the water heater and furnace system further comprise a one-
way
valve downstream of the heater core and upstream of the storage tank to
prevent water from
flowing from the storage tank to the heater core.
Also, embodiments can include wherein the housing is sealed off from an
interior of the
RV.
Additionally, embodiments can include wherein the heater core comprises a
plurality of
spaced apart fins configured for convective heat transfer from the water
running through the
heater core to the fins to heat the air.
Some embodiments of the water heater and furnace system include wherein the
heater
core further comprises a pneumatic resistance screen to reduce the velocity of
the air moved
through the blower to increase the heat transfer from the heater core to the
air as the air passes
through the heater core.
Also, embodiments can include a mixing valve upstream of the system hot water
outlet
and downstream of the water inlet and the heater core, said mixing valve for
mixing cold water
stream from the water inlet with hot water heated by the burner to then
discharge out the hot
water outlet.
Additionally, embodiments can further include a relay connected to the burner
to prevent
the burner from switching to a low setting from a high setting when the blower
and the burner
are both operating.
Additionally, embodiments can include an exhaust system coupled to a top end
of the
heat exchanger to collect combustion byproducts of the burner, and direct the
combustion
byproducts outside the housing.
Some embodiments of the water heater and furnace system include an air plenum
to
collect and deliver the heated air to heating ducts.
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Also, embodiments can include a solenoid valve coupled downstream of the
storage tank
and configured to control flow of the water from the storage tank to the heat
exchanger.
Additionally, embodiments can include a manifold attached to the storage tank,
wherein
the manifold is configured to convey water from the heater core to an upper
region inside the
storage tank.
Also, embodiments can include wherein the manifold is configured to convey the
water
from a lower region inside the storage tank to the pump.
Aspects of the invention relate to a method for regulating water outlet
temperature and
space heating of a hydro-furnace for a recreational vehicle (RV) comprising
circulating water
from a water inlet to a heat exchanger for heating the water flowing through
the heat exchanger,
and then directing the heated water through a heater core and then to a
storage tank, heating air
flowing across the heater core; heating the water running across the heat
exchanger to produce
heated water with a burner; pulling return air through the heater core with an
air blower; and
heating the return air with the heated water to produce heated air.
Embodiments of the method further include mixing the heated water with supply
water
to produce hot water at a hot water temperature set point.
Also, embodiments of the method can include wherein the desired hot water
temperature
is 120 degrees F.
Additionally, embodiments can include monitoring the temperature of water in
the
storage tank and sending a signal to the burner to turn on to heat the heat
exchanger if the
temperature of the water in the storage tank is below 140 degrees F.
Also, embodiments of the method can include activating the pump if the burner
is on.
Embodiments of the method further include turning off the burner if the
temperature of
the water in the storage tank is greater than 160 degrees F.
Aspects of the invention relate to a water heater and furnace system for a
recreational
vehicle (RV) comprising a heat exchanger configured to heat water received
from a water supply;
heater core and a blower, the heater core being located remotely from the heat
exchanger, the
heater core being fluidly coupled to the heat exchanger by a first length of
pipe, and the blower
being configured to move air through the heater core and deliver heated air
outside of a housing
that houses the heater core and the heat exchanger; a storage tank configured
to store water passed
through the heater core, the storage tank being located remotely from the heat
exchanger and the
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heat core, the storage tank being fluidly coupled to the heater core by a
second length of pipe,
wherein said water heater and furnace system is configured to permit
concurrent delivery of
heated air outside the housing and heated water to a system hot water outlet.
Additionally, embodiments can include a solenoid valve coupled downstream of
the
storage tank and configured to control flow of the water from the storage tank
to the heat
exchanger.
The description set forth below in connection with the appended drawings is
intended as
a description of the presently preferred embodiments of a combination water
and air heating
system for a recreational vehicle (RV) provided in accordance with aspects of
the present
assemblies, systems, and methods.
A combination water and air heating system or "hydro-furnace" for a mobile
vehicle,
which can include a recreational vehicle (RV), a boat, a mobile home trailer
or fifth wheel, is
provided in accordance with aspects of the present disclosure. The hydro-
furnace can function
as both a water heater and a space heater by supplying both hot water and hot
air through three
basic systems: a boiler system, a recirculating system, and a radiator system.
Heated water and
heated air can be generated concurrently or serially. Generally speaking, the
boiler system can
provide a heat source for water running therethrough by combusting air and
fuel, such as propane,
and exhausting combustion products to provide on-demand hot water and hot
water for a storage
tank.
Because fuel and byproducts of fuel are involved, the boiler system can be
sealed off from
the recirculating system and the radiator system to prevent combustion
byproducts and unused
fuel from entering the RV and potentially circulating harmful gas throughout
the mobile vehicle.
For purposes of the following disclosure, reference is made to an RV although
other mobile
vehicles can use the hydro-furnace of the present disclosure.
To increase the temperature inside the RV, the recirculating system can heat
return air
drawn from inside the RV using the water heated in the boiler system as the
heat source, and
deliver the heated air back inside the RV. The radiator system can store
heated water and heat
the return air when hot air is desired. As described in further detail below,
the boiler system can
include gas and electrical controls, a burner, a heat exchanger, a water pump,
water tubing
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and connections, and an exhaust system. The recirculating system can include a
blower, a heater
core, a return air port, and water tubing and connections. The radiator system
can include a
radiator tank, an air plenum and duct ports, and water tubing and connections.
However,
components of the three systems can be re-arranged within the housing of the
hydro-furnace
without deviating from the scope of the invention.
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Each of the three systems can be contained within one or more chambers or
compartments within a housing. The components contained in the housing can
include gas lines,
water lines, sensors, switches, mechanical and electromechanical components.
and electronics
for controlling the flow and operation of both the fuel and water flowing into
and/or through the
hydro-furnace. Note that a hydro-furnace for an RV, such as the hydro-furnace
disclosed herein,
is different from a portable water heater and a portable room heater, which is
understood to be
portable but not necessarily for the heavy duty use and more rigid
requirements for RVs.
The housing can comprise a plurality of removable panels mounted together to
form two
or more sides of the hydro-furnace and enclose the various components inside
the hydro-furnace.
Any number of panels and sub-panels can be included to form the outer surface
of the hydro-
furnace and divide an interior of the housing into separate smaller housings
or compartments to
house components of each of the three systems. In some examples, one or more
of the panels of
the housing can be permanent or non-removable from a housing frame.
The housing can be divided into a radiator compartment at a back side or
second side of
the hydro-furnace and a main compartment at a front side or first side of the
hydro-furnace. The
main compartment can be further divided into a blower compartment and a burner
compartment.
The burner compartment can be located on a left side of the hydro-furnace,
from the perspective
of the first side looking at the second side and the blower compartment is
located on a right side
of the hydro-furnace.
In another embodiment, the burner compartment can be located on the right side
of the
hydro-furnace and the blower compartment is located on a left side of the
hydro-furnace. Said
differently, the burner compartment and the blower compartment can be located
along a first side
or a front side of the housing, and the radiator compartment can be located
along a second side or
a back side of the housing directly opposite the first side. The components of
the radiator
system, the recirculating system, and the burner system can cooperate by
extending through the
interior sections of the housing.
For purposes of the following discussions, the first side or front side of the
housing can
also be considered the front of the hydro-furnace, and the second side or back
side of the housing
can be considered the back of the hydro-furnace. One of ordinary skill in the
art will recognize
that these directional assignments to the components of the housing and the
hydro-furnace are for
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purposes of description only as the hydro-furnace may be installed in any
orientation that allows
for proper operation.
The housing includes vents, input and output connectors, and interface ports
for
connecting the hydro-furnace to the RV. A burner inlet vent for introducing
air outside of the
housing into the burner compartment can be located at the front side of the
housing. A burner
outlet vent for channeling combustion byproducts of a burner for heating a
heat exchanger,
unburned fuel, and other gases outside the burner compartment can be located
above the burner
inlet vent at the front side of the housing. Thus, the burner inlet vent and
the burner outlet vent
are provided on a front side of the hydro-furnace. The burner compartment can
be sealed off
from the other compartments to prevent the combustion byproducts of the
burner, unburned fuel,
and other gases inside the burner compartment from entering the blower
compartment and the
radiator compartment of the housing and mixing with the heated air to be
delivered inside the
RV. For example, ducting can be connected to the burner outlet vent to direct
the exhaust gas to
the exterior of the RV.
A fuel or gas inlet for introducing fuel to the burner in the burner
compartment can
extend out from a third side or left side of the housing. Alternatively, the
gas inlet can be located
on a front side of the housing. In another embodiment, the gas inlet is
located on a right side of
the housing, depending on the location of the burner compartment within the
housing. Again,
the orientation of the various components relative to the housing is not
crucial and can vary
without deviating from the scope of the present invention.
A fuel or gas line can be connected to the gas inlet to supply fuel, such as
propane, to the
burner. The gas inlet can be a male connector but a female connector can
optionally be used, in
which case a gas line having a male connector tip can engage the female
connector to supply fuel
to the hydro-furnace. A gas tubing or line can be provided to connect the gas
inlet to a gas
control valve, which can be connected in line to a burner to control gas flow
from a gas source
through the burner of the hydro-furnace. Other valves, such as linear or equal
percentage valves,
are contemplated for use with the present system to regulate gas flow through
the hydro-furnace.
Control of the gas control valve can be based on various sensed parameters,
such as water
flow, inlet and/or outlet water temperatures, and set point. In one
embodiment, the gas control
valve is a linear valve. In an example, the linear valve is provided by CAE,
model number CPV-
H2467AY, which can be used to control gas flow through the hydro-furnace. An
additional
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valve in line with the gas control valve may be used to further control gas
flow, function as an
emergency shut off valve, or any desired function. The additional valve can be
an on/off
solenoid valve that can function as an emergency shut off valve and that can
receive operating
signals from an emergency cut off switch (ECO), which can be a hi-metallic
switch.
The gas control valve can be connected to a microprocessor of a controller,
which can be
programmed to control the gas control valve based on data and signals received
from sensors
such as thermostats or thermistor probes. In general, the gas control valve
can be an on/off valve
with a high/low setting. Alternatively, an additional valve can be an on/off
valve and the gas
control valve can be regulated to control gas flow from a high setting to a
low setting. Together,
the gas control valve and the additional valve may also act as a dual
emergency shut off valve
when both are in the off position. In one example, the hydro-furnace may
accept propane gas
only, such as while travelling with propane tanks or when parked at a camp
site. In another
example, the hydro-furnace may accept another type of fuel that can be
supplied through the gas
inlet valve, such as a gas source at a camp site.
A DC connector port for powering the hydro-furnace can be located adjacent the
gas inlet
valve. In an example, the DC connector port is a passage or bore through the
housing having a
plastic ferrule or liner that allows one or more cables to pass therethrough
for connections
between the electric system of the hydro-furnace, including the controller or
DSI board inside or
adjacent to an ignition control box discussed in detail below, and the
vehicle's electric system.
A water inlet for introducing water from a water supply into the radiator
compartment
can extend out from a fourth side or right side of the housing opposite the
left side of the
housing. Alternatively, the water inlet can be installed extending from the
same side but from
the blower compartment. A water outlet for delivering heated water out from
the hydro-furnace
can extend out from the fourth side or right side of the housing adjacent to
the water inlet. The
water inlet and the water outlet can be mounted side-by-side or one above
another elevation-
wise. The location of the water inlet and the water outlet is not limited, and
can also be located
on other sides of the housing or separately on different sides of the housing.
A voltage connector port for powering the hydro-furnace can be located
adjacent the gas
control valve or at some other accessible location within the housing. In an
example, the voltage
connector port can be a DC connector port. The DC connector port can be a
passage or bore
extending through the housing having a plastic ferrule or plastic liner that
allows one or more
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cables to pass therethrough for connections between the electric system of the
water heater, such
as the controller, and the vehicle's electric system. The voltage connector
port may also be
sealed air-tight to prevent gases in the burner chamber from leaking out other
than the burner
outlet vent.
A first or upper return air vent and a second or lower return air vent can
extend through
the second or back side of the housing to allow return air outside the housing
to be pulled into
the blower compartment of the hydro-furnace through the radiator compartment.
A heater core
located in the blower compartment by a blower is provided for heating the
return air. A filter,
such as a HEPA filter or other high efficiency filters, can be provided at the
upper return air vent,
the lower return air vent, or both vents, so that the return air can be
filtered before it is heated and
delivered. This can also ensure cleanliness of the components in the system.
The filter can be
installed inside or outside of the housing. If installed outside the housing,
the filter can be easily
attached and detached easily from the hydro-furnace for cleaning or
replacement, such as in a
cartridge compartment attached to the housing.
The radiator compartment can be rectangular shaped and formed from a C-shaped
radiator housing panel having a central panel and two subpanels extending from
opposite edges
of the central panel. A left side radiator housing panel and a right side
radiator housing panel
can attach to the ends of the central panel and the two subpanels of the C-
shaped radiator
housing panel. A radiator housing door, which comprises air vents, can attach
to the remaining
free ends of the two subpanels of the C-shaped radiator housing panel to cover
the opening
opposite the central panel of the C-shaped radiator housing panel.
The upper return air vent and the lower return air vent are located on the
radiator housing
door. Thus, the radiator housing door can also be the back side of the
housing. An optional
radiator housing divider can be positioned inside the radiator compartment to
subdivide the
radiator compartment into separate smaller compartments. The radiator housing
divider can
extend from the central panel of the C-shaped radiator housing panel to the
radiator housing door
between the upper return air vent and the lower return air vent to divide the
radiator compartment
into an upper radiator chamber and a lower radiator chamber. Thus, return air
can be drawn into
the upper radiator chamber through the upper return air vent and return air
can be drawn into the
lower radiator chamber through the lower return air vent. The lower radiator
chamber can house
a radiator tank to preheat the return air as further discussed below.
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Adjacent the radiator compartment is the main compartment, which can polygonal
shape,
such as a rectangular shape, and formed from a C-shaped main housing panel
having a central
panel and two subpanels extending from opposite edges of the central panel. A
left side main
housing panel and a right side main housing panel covering the ends of the C-
shaped main
housing panel or, more specifically, attached to the ends of the central panel
to form an
enclosure. The two subpanels of the C-shaped main housing panel and a radiator
housing door
are attached to the remaining free ends of the two subpanels of the main
housing panel to cover
the opening of the C-shaped main housing panel opposite the central panel of
the C-shaped main
housing panel.
A main housing divider can be positioned inside the main compartment to
subdivide the
main compartment into the blower compartment and the burner compartment. The
main housing
divider can extend between the subpanels, the central panel of the C-shaped
main housing panel,
and the main housing door to divide the main compartment into a left
compartment or the burner
compartment and a right compartment or the blower compartment.
The burner inlet vent and the burner outlet vent for providing ventilation for
only the
burner compartment can be located on the main housing door. Thus, the main
housing door can
be the first or front side of the housing. The main housing divider can be
provided to effectively
seal the burner compartment from the blower compartment to prevent fuel and
combustion by
products from entering into the blower compartment.
Air passages and water lines or tubing can extend between the radiator
compartment, the
adjacent blower compartment, and the adjacent burner compartment through one
or more cutouts
defined in both of the central panels of the C-shaped radiator housing panel,
the C-shaped main
housing panel, and the main housing divider. The various cutouts between the
central panels and
other internal panels allow the components, such as cables, wires, tubing,
lines, fittings, brackets,
electronics, fans, etc., from each system to connect to another system. Any
cutouts between the
burner compartment and any other compartment to allow components to extend
therethrough can
be sealed with components extending therethrough to prevent gases from leaking
into the blower
compartment or the radiator compartment. Optionally, sealants, fire retardant
fabric or cloth, or
other paneling means for isolating the different compartments can be used.
The cutouts between adjacent compartments can be similarly shaped and aligned
to each
other. In one example, an upper first cutout, a second cutout below the upper
first cutout, and a
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lower third cutout below the second cutout of the central panel of the C-
shaped radiator housing
panel can align with similarly shaped cutouts on the main housing panel. In an
example, the first
cutout can be rectangular, the second cutout can be circular, and the third
cutout can be
rectangular. The cutouts on the main housing panel therefore include an upper
rectangular
cutout or first cutout, a second cutout or a circular cutout below the upper
rectangular cutout, and
a third cutout or a lower rectangular cutout below the circular cutout of the
central panel of the
C-shaped main housing panel. Alternatively, a single panel can divide the
radiator compartment
from the main compartment so that alignment of cutouts from different panels
is not necessary.
When hot water and/or hot air is desired, the hydro-furnace can be powered on
to activate
the electrical and electro-mechanical components of the system. If water is
not already present
in the hydro-furnace, water can be directed from a water supply through the
water inlet into a
radiator tank located in the radiator compartment and to a mixing valve
located in the blower
compartment. Water line pressure or from a pump can move the water through the
system.
Initially, the temperature of the water in the radiator tank may be at or near
the
temperature of the inlet water flowing through the water inlet. Eventually,
the temperature of the
water in the radiator tank will increase as it circulates through the hydro-
furnace. The radiator
tank is configured to store the heated water and transfer heat from the stored
heated water to the
return air flowing past the radiator tank when the blower is on to heat the
return air as discussed
further below. The mixing valve can regulate fluid flow between heated water
leaving the heater
core and water from the water inlet. That is, the mixing valve can mix the
water at the two
different temperatures from the two different sources to achieve a desired
downstream or outlet
water temperature of the water exiting the hot water outlet. Said differently,
the mixing valve
can mix the water from the water inlet with the heated water from the heater
core to provide hot
water at the desired outlet water temperature.
In one example, the desired outlet water temperature of the hot water leaving
the hydro-
furnace through the hot water outlet can be 120 degrees F. Thus, the mixing
valve has two
inputs and one output. The mixing valve can be a manually operable control
valve or an
electronically adjustable control valve. The outlet water temperature can be
adjusted by
controlling the mixing valve. In one embodiment, a microprocessor of a
controller can send
signals to adjust the mixing valve to produce a desired outlet water
temperature using feedback
from a temperature sensor located at or near the hot water outlet.
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Before hot water can be dispensed from the hot water outlet, the water inside
the radiator
tank can be heated to an acceptable temperature. To do so, the water can be
circulated from the
radiator tank by a pump, to a heat exchanger where the water is heated by a
burner. The heat
exchanger can be heated directly or indirectly by a burner located in the
burner compartment.
The burner can burn fuel fed from the gas inlet to produce combustion gases to
heat the water in
the heat exchanger. In one example, the fuel is liquefied petroleum (LP) gas
or propane. The
heat exchanger can transfer heat from the combustion gases to the water.
From the heat exchanger, the water is pumped to a heater core. At least some
of the heat
from the heated water in the heater core can be drawn or pulled by a blower
when powered on to
provide heated air. The blower can heat return air in the RV by pulling the
return air past the
radiator tank and through the heater core before delivering the heated air to
an air plenum and
back to the RV through heating ducts. Return air drawn through the lower
return vent passing
over the radiator tank can also transfer heat by convection to the surrounding
return air. More
specifically, when a heat request is generated by a room thermostat (RTS) for
space heating, the
blower can turn on to pull return air from the upper and lower radiator
chambers of the radiator
compartment through the heater core to supply heated air to an air plenum
located in the radiator
compartment or blower compartment.
The air plenum is connected to heating ducts extending outside the hydro-
furnace. The
air plenum can accumulate the hot air from the heater core at an elevated
pressure to force and
direct the hot air into the heating ducts, which lead air back inside the RV.
In one example, the
entire blower compartment can be the air plenum. Return air circulating in the
lower radiator
chamber can be preheated from the radiator tank to increase the efficiency of
the system. When
the blower is activated to generate heated air, the heater core can provide
convective heat transfer
from the heated water running through the tubing inside the heater core to the
return air drawn in
from the upper radiator chamber and the lower radiator chamber until the
desired room
temperature is reached, at which time the RTS can send a signal to shut off or
deactivate the
blower.
From the heater core, the heated water flows through a one-way valve before
returning
back to the radiator tank. Thus, a heating loop can be formed from the
radiator tank, the heat
exchanger, the heater core, and back to the radiator tank. The one-way valve
can be provided
downstream of the heater core to prevent water from the water inlet to enter
the heater core or
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flow through the water outlet other than through the mixing valve. The one-way
valve can
ensure only heated water leaving the heater core can pass through the mixing
valve.
The pump can be located downstream of the radiator tank in the blower
compartment, but
also can be located in the burner compartment, the radiator compartment along
the heating loop,
or elsewhere within the housing. In one example, the pump is an electric
activated water pump
controlled by a microprocessor of a control board and operated to circulate
the water through the
heating loop when the hydro-furnace is powered on and a temperature of the
water in the radiator
tank is below a minimum tank temperature to provide hot water and/or heated
air.
The pump can continually circulate the water through the heat exchanger until
the
average temperature of the water in the radiator tank reaches a threshold
temperature, such as,
for example, 160 degrees F or some different set point temperature. Once the
average
temperature of the water in the radiator tank reaches the threshold
temperature, such as 160
degrees F, the pump and the burner can shut off. If the water in the radiator
tank falls below a
minimum tank water temperature, such as 140 degrees F, the pump and the burner
can switch on
until the average temperature of the water in the radiator tank returns back
to the threshold
temperature, such as 160 degrees F. Thus, the water in the radiator tank can
be maintained
between 140-160 degrees F.
As hot water is being dispensed through the hot water outlet, water from the
water supply
can enter the radiator tank to replace the dispensed hot water. Because the
newly introduced
water is typically lower in temperature than the temperature of the water in
the radiator tank, the
new combined temperature drops from the previous tank temperature. When the
temperature of
the water in the radiator tank falls below the minimum tank temperature, the
pump and the
burner are activated to generate heat and produce additional heated water
until the minimum tank
temperature is reached. The hydro-furnace is capable of producing hot water as
hot water is
continually used. Thus, the hydro-furnace can also function as a tankless
water heater.
The water supply inlet and the water outlet can be in line with each other and
connected
with the tubing. The water supply inlet and the hot water outlet can be
located externally of the
housing, such as externally of the left side of the hydro-furnace of the
housing for quick access
by a user. The gas inlet can be located on the right side of the hydro-
furnace.
Optionally, tubing and mechanical and electrical components can be located, at
least in
part, outside of the panels of the housing to facilitate assembly and
maintenance, among other
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things. Incoming water or water to be heated from a water supply or source can
enter the hydro-
furnace through the water inlet extending out of the housing. In one example,
the water inlet can
be a threaded male connector for engaging a threaded female connector from a
water supply. In
another example, the water inlet can be a smooth pipe with or without a hose
barbed end to
receive a hose or tubing connected to the water supply. A clamp can further
secure the hose or
tubing to the water inlet.
The water inlet can have a standard fitting to readily accept a water feed
line or inlet
water source. For example, the water supply inlet can comprise an industry
standard connection
fitting for attaching to a water supply or cold water supply line. The hot
water outlet similarly
can comprise an industry standard connection fitting for attaching to plumbing
lines that then
carry heated water to user stations, such as to sinks and baths/showers
located elsewhere in the
RV on which the hydro-furnace for the RV is mounted. In one example, the water
supply inlet
and hot water outlet can include a quick connect coupling or a threaded
collar.
Unlike a water heater or furnace installed in a permanent structure, such as
in a home
which has a generally stable water supply temperature and pressure, an RV with
a hydro-furnace
moves from water supply source to water supply source when on the road
travelling from point
A to point B, etc. The hydro-furnace for the RV should be able to produce
water at the desired
temperature from widely varying water supply temperatures while still
maintaining a relatively
small size or profile to fit within the portable environment of the RV.
The water inlet inside the housing can transition into a multi-flow fitting,
such as a four
way pipe fitting or a four way tee, used to combine and/or divide fluid flow.
In an example, the
multi-flow fitting can be four individual fittings oriented 90 degrees apart
to for a four way tee.
However, multiple back to back tees can be used to split the flow into
multiple streams. In one
example, the water inlet is coupled to a first fitting of the four way tee, a
hot water return line
from the heater core is coupled to a second fitting of the four way tee, the
radiator tank is
coupled to a third fitting of the four way tee, and a mixing valve is coupled
to a fourth fitting of
the four way tee via a cold water output line. Thus, the four way tee allows
water from the water
inlet to flow into the radiator tank and to the mixing valve, which is further
discussed below.
The radiator tank is located in the radiator compartment and can store water
received
from the water inlet and the hot water return line. The temperature of the
water inside the
radiator tank can be monitored by one or more temperature sensors and
maintained and
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controlled at an optimum tank temperature, such as between 140-160 degrees F,
using control
circuitries, a controller, or a control board.
As the temperature of the water inside the radiator tank increases, so does
the temperature
of the radiation tank. A tank emergency cutoff thermostat (TECO) for
preventing the
temperature of the water inside the radiator tank from increasing past a
maximum tank water
temperature, can be positioned on a surface of the radiator tank. In one
example, the maximum
tank water temperature is 170 degrees F. In another example the maximum tank
water
temperature can be other than 170 degrees F. In one embodiment, the TECO can
be a disc
thermostat that prevents the burner from firing when the temperature of the
water in the radiator
tank exceeds the maximum tank water temperature.
As previously mentioned, return air can be pulled by a blower located in the
adjacent
blower compartment, from both the upper radiator chamber, which draws the
return air from
outside the hydro-furnace through the upper return air vent, and the lower
radiator chamber,
which draws the return air from outside the hydro-furnace through the lower
return air vent. In
one example, the radiator tank can be located in the lower radiator chamber of
the radiation
compartment. Thus, the return air in the lower radiator chamber can be
preheated by convective
heat transfer from the radiator tank as it travels from the radiator
compartment to the blower
compartment.
The radiator tank can comprise a radiator tank body having a storage space
configured to
store the heated water, an inlet radiator cover at an inlet end of the
radiator tank body, and an
outlet radiator cover at an outlet end of the radiator tank body. A plurality
of fins extending from
the exterior of the radiator tank body may also be provided to increase
convection from between
the radiator tank and the return air in the radiator compartment.
The inlet radiator cover can be similar or identical to the outlet radiator
cover. The inlet
and outlet radiator covers can be circular and sized to fit at opposite ends
of the radiator tank
body to cover the interior space of the radiator tank body. A watertight seal
such as an 0-ring or
gasket can be provided between the radiator covers and the radiator tank body.
An inlet opening
through the inlet radiator cover can allow water from the inlet and/or the hot
water return line
from the heater core to flow inside the radiator tank body. An outlet opening
through the outlet
radiator cover can allow water from inside the radiator tank body to flow to
the heat exchanger.
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A size or diameter of the inlet and outlet openings can be smaller than a size
or diameter
of the interior cavity or bore of the radiator tank body so that a volume of
water can be
maintained inside the radiator tank body. In one example, the radiator tank
body can store 2-4
gallons of water. In other examples, the tank body can store a different
volume of water. The
location of the inlet opening and the outlet opening can affect water flow and
temperature mixing
inside the radiator tank body. In one example, the inlet opening can be
adjacent an outer
perimeter of the inlet radiator cover, and the outlet opening can be adjacent
an outer perimeter of
the outlet radiator cover, with the inlet opening and outlet opening
diametrically opposed at
opposite ends of the heat exchanger to provide a longer path through the
radiator tank body.
This can ensure better mixing than a shorter direct path between the inlet and
outlet openings.
Water from the radiator tank can exit out the outlet and flow to the heat
exchanger via a
radiator tank output line. A pump can be positioned inline and downstream of
the radiator tank
along the radiator tank output line. In one example, the pump can be located
between the heat
exchanger and the radiator tank along the radiator tank output line inside the
blower
compartment. The pump can be a standard electric driven water pump. The pump
can be
controlled directly or indirectly by control circuitry. Water can be pumped
out from the radiator
tank to the heat exchanger where it is heated and passes through the heater
core before being
dispensed through the mixing valve to the water outlet and to a faucet or
shower and/or return
back into the radiator tank, thus forming the heating loop. The pump can
actively circulate the
water until the radiator tank reaches some set point, such as 160 degrees F,
at which time the
burner can switch off. The pump can be shut off simultaneously with the burner
or a short time
thereafter. In other examples, the pump can be positioned anywhere along the
heating loop as
described above.
A low temperature sensor (LTS) or alternatively an input temperature probe
(Tin) for
measuring the temperature of the water can be connected inline and downstream
of the radiator
tank. The LTS can be a disc thermostat that provides a heat request signal to
the burner when the
water temperature in the radiator tank drops below a minimum tank water
temperature. The Tin
can be a thermistor probe that monitors the water temperature. In one example,
the minimum
tank water temperature is 140 degrees F. In the illustrated embodiments. the
LTS or Tin can be
located downstream of the radiator tank before reaching the pump or downstream
of the pump at
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or before the heat exchanger. Other sensors can be used or a combination of
sensors can be used
to read and provide input to the controller to control the burner.
The radiator tank output line can be coupled to a heat exchanger tubing. The
heat
exchanger tubing can wrap around the exterior of the heat exchanger, which can
be a conductive
body having a skirt or a plenum. The plenum and the heat exchanger tubing can
be made of a
conductive material, such as aluminum, copper, copper alloy, brass, brass
alloys, or other
conductive metals. In other embodiments, the plenum and the heat exchanger
tubing may be
made from other corrosive resistant materials, or plated or coated with
corrosive resistant
material, that are able to withstand the direct or indirect heat of the
burner.
The heat exchanger tubing can wrap around the plenum so that water flows from
a
bottom end of the plenum, elevation-wise, towards a top end of the plenum
inside the tubing, and
by conduction is heated by the plenum which then heats the water running
through the heat
exchanger tubing, similar to a preheat. Because both the plenum and the heat
exchanger tubing
can be made from a conductive material, heat energy is transferred by
conduction from the
plenum to the heat exchanger tubing and from the heat exchanger tubing to the
water running
therein. As a result, the water running around the plenum inside the tubing is
pre-heated before
entering the heat exchanger. The water in the heat exchanger tubing then
enters the heat
exchanger so as to be heated by the heated gas from the burner, as further
discussed below.
The plenum can have an opening with a passage extending from the bottom end to
the top
end. Within the plenum, a plurality of spaced apart internal fins can be
located in the opening
between the bottom end and the top end to provide additional heat transfer
paths to the heat
exchanger. In one example, the internal fins are located near the top end to
provide space for the
burner. The internal fins can be closely spaced or loosely spaced inside the
plenum to form
baffles or channels for the flow of heated air from the bottom end of the heat
exchanger and then
rising through the internal fins and out the top of the heat exchanger,
elevation-wise. The
number of internal fins and the surface area of each of the internal fins can
depend on the desired
heat exchange rate by convection, conduction, and radiation exchanging with
the interior run line
of the heat exchanger tubing.
The heat exchanger tubing passes through the internal fins and wherein U-
shaped returns
are provided on outer surfaces on opposite sides of the plenum to connect the
parallel tubing
sections in a serpentine fashion within the interior space of the plenum.
Thus, the heating pipe
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can form continuous passes through the opposite sides of the plenum and the
internal fins to
maximize the heat transfer from the internal fins to the heat exchanger tubing
to heat the water
flowing therein. The number of fins and the total tubing length passing inside
the plenum can be
selected to control the residual time of water travelling through the plenum
and the amount of
heat transferring directly from the burner to the plenum and from the burner
to the fins and then
to the heat exchanger tubing.
An exhaust system comprising an exhaust conduit can be provided to collect
exhaust
fumes rising from the burner and direct the exhaust fumes away from and
outside the burner
compartment through the burner outlet vent. The exhaust system can be
positioned at the top of
the plenum and coupled directly to the top end of the plenum. The exhaust
system can extend
horizontally towards the burner outlet vent. The exhaust system can have a
larger opening at the
output end to provide an open flow path to the burner outlet vent for the
combustion byproducts.
The exhaust system can be sealed to ensure the combustion byproducts flow
directly out
the burner outlet vent. An exhaust fan powered by an exhaust fan motor may
also be provided to
assist directing the exhaust fumes through the burner outlet vent. The exhaust
fan may be
connected to a microprocessor of a controller such as the DSI board explained
further below.
The DSI board can operate the exhaust fan motor to turn the exhaust fan on and
off based on
signals sent to the microprocessor from one or more sensors. For example,
whenever the burner
is activated to burn fuel, the exhaust fan is also activated to exhaust gas.
The exhaust fan can
also be activated when the burner is not in service to move air through the
system for cooling or
venting purposes. A vent duct may also extend away from the housing
surrounding the burner
outlet vent to direct the exhaust fumes away from the hydro-furnace and the
RV. The exhaust
fan may be located inside the vent duct instead of inside the housing.
Additional ducting may be provided to direct the exhaust gas through the
burner outlet
vent and out, such as out an opening to an exterior of the mobile or
recreational vehicle. In some
examples, an induced draft fan, a force draft fan, or both can be incorporated
to move gas
through the hydro-furnace.
In some examples, inlet and outlet headers are provided within the heat
exchanger. For
example, the heat exchanger tubing can direct inlet water to the inlet header
that then separates
the single inlet feed line into multiple parallel run lines inside the heat
exchanger. The multiple
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run lines are then routed to an outlet header that then consolidates the
various run lines into a
single outlet line, which then exits the heat exchanger and flow into the
discharge or outlet line.
The heat exchanger tubing can wrap around the plenum of the heat exchanger
three times
in the form of loops, such as continuous loops or in sections that are joined.
In other
embodiments, the heat exchanger tubing may have fewer than three loops
wrapping around the
plenum or more than three loops wrapping around the plenum. The length of the
heat exchanger
tubing and the number of loops formed or wrapped around the heat exchanger can
depend on the
residual time desired to route the water through the heater, the number of tic-
ins needed to
connect the various component, and the desired preheat, among others.
The burner can be positioned immediately adjacent the heat exchanger and
provide the
heating source to heat the exchanger. In an example, the burner is positioned
below the heat
exchanger, elevation-wise, so that hot air and combust gas generated from the
burner rise
through the heat exchanger. In an example, the burner can have a wide tip
having multiple gas
discharge holes to provide a large distributed flame profile. The tip can
comprise a plurality of
plate-like structures positioned side-by-side with each plate having a
plurality of discharge holes
formed on an edge thereof for gas flow. The tip can alternatively have a
circular ring shape, a
rectangular shape, an elliptical shape, a square shape, or other shaped tips
provided the number
of discharge holes are selected to produce sufficient BTU for a given gas type
and gas pressure.
The burner can comprise a burner pad extending at least partially into the
plenum through
the opening at the bottom end to provide heat inside the plenum. The amount of
heat provided to
the plenum to heat the water circulating in the heat exchanger tubing depends
on the power
output of the burner. The burner generates heat by the combustion of gas. The
fuel or gas is
supplied to the burner through the gas inlet extending outside of the housing.
The gas is directed
from the gas inlet to a fuel or gas control valve, which is configured to
control the flow of gas
into a burner pad located beneath or at least extending partially inside the
boiler heat exchanger
through the bottom end of the boiler heat exchanger. In one embodiment, the
gas control valve
can open and operate in one of two stages: a high stage (HI) and a low stage
(L0), as discussed
further below. When not in use, the gas control valve can cut off the supply
of gas or shut off.
When the gas control valve is on HI, the output of gas is at a high BTU
rating, and when the gas
control valve is on LO, the output of gas is at a lower BTU rating.
Alternatively, the can control
valve can be a variable gas control valve.
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The multiple gas discharge holes of the burner pad can be a series of nozzles
for the gas
to pass therethrough. An ignition control box can comprise a direct spark
ignition (DSI) board
having a microprocessor and ignition control electronics including a spark
igniter, which can be
controlled to ignite the gas leaving the nozzles to combust the gas and
produce heat. The
ignition control box and the gas control valve can be controlled directly or
indirectly by control
circuitry.
The heat exchanger tubing can exit the heat exchanger and connect to an input
port of the
heater core via a connector tubing. The heat exchanger tubing cam exit the
heat exchanger near
the top end of the heat exchanger. A boiler heat exchanger emergency cutoff
thermostat (BECO)
can be provided to detect whether the temperature of the water leaving the
heat exchanger
exceeds an absolute maximum heated temperature to cut power to the burner. In
one example,
the absolute maximum heated temperature is 185 degrees F with other maximum
values
contemplated, such as lower or higher than 185 degrees F. The BECO can be
connected inline
and downstream of the heat exchanger. In one example, the BECO is a disc
thermostat that turns
off the burner, or sends signals to the controller to then turn off fuel to
the burner, when the
water temperature at the output of the heat exchanger exceeds 185 degrees F.
In an example,
when the max temperature is sensed, the emergency shut off valve is activated
to block all fuel to
the burner. When the burner is not on, the pump can also turn of. Conversely,
the pump can be
operational when the burner is on.
A high temperature sensor (HTS) or an output temperature probe (Tout) for
monitoring
the temperature of the water downstream of the heat exchanger can be placed
adjacent,
downstream or upstream, to the BECO to stop the burner when the water
temperature at the
output of the heat exchanger exceeds a maximum heated water temperature. In
one example, the
maximum heated water temperature can be 175 degrees F.
The heater core can transfer heat from the water to the return air supplied by
the blower.
The heater core comprises a core body having a box like shape mounted in the
blower
compartment on a panel separating the radiation compartment from the blower
compartment.
The core body can have a hollow rectangular shape with a rear opening facing
the radiator
compartment and a front opening facing towards the blower. Flanges can extend
from each side
of the rear opening to attach to the central panels of the radiator housing
and/or main housing.
The rear opening can communicate to the radiator compartment, and more
specifically, the upper
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and lower radiator chamber through the upper rectangular cutouts. The front
opening can be
coupled directly to a suction port of the blower.
The blower circulates air from the interior space of the mobile vehicle or RV
through the
radiator tank and the heater core to the air plenum and back to the room
through air ducts. The
blower has a suction port to draw in air and a blower port to blow air out.
Thus, the blower can
function as a vacuum. Alternatively, the ports can be reversed, or a different
type of blower can
be used, as desired.
A room thermostat (RTS) outside the hydro-furnace can be preprogrammed or
operated
by a user to generate and transmit a heat request for air heating or space
heating. The RTS can
be connected to control circuity of the hydro-furnace to activate the pump,
the burner, and the
blower when powered "ON". The RTS can also send signals to the control
circuitry of the
hydro-furnace to stop the blower, pump, and/or burner when an interior set
point is reached.
In one embodiment, the gas control valve can be set between a high setting
(HI) and a
low setting (HI). Alternatively, the gas control valve can be variable. The
gas control valve can
be normally set on HI until the water in the radiator tank is within the
minimum tank water
temperature and the threshold temperature, such as between 140-160 degrees F,
or above the
threshold temperature, at which time the gas control valve can switch to LO.
In one example, when the blower is activated by the RTS, the power to the
blower is
applied to this connection and reduces the output of gas to the lower BTU
rating. That is, the gas
control valve is on LO. The burner can also be activated by the RTS when the
RTS is not
powered "ON" and the water temperature in the radiator tank falls below the
minimum tank
water temperature, such as, in one example, 140 degrees F. Thus, when water is
to be heated or
air is to be heated, but not both, the gas control valve can operate on LO.
When both water and
space are to be heated simultaneously, the gas control valve can be on HI. In
an example, the LO
setting can be about 12K to about 18K BTU, and the HI setting can be about 35K
to about 37K
BTU. A relay (R) can prevent the gas control valve from switching to LO if
both the water
heating and space heating are used simultaneously. The pump can be operating
continuously
while the burner is on.
Within the core body of the heater core, a plurality of spaced apart fins are
provided. The
fins can be closely spaced or loosely spaced inside the core body to form
baffles or channels for
the flow of return air from the radiator compartment through the heater core
generated by the
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suction of the blower. The number of fins can depend on the desired heat
exchange rate by
convection, conduction, and radiation exchanging with the interior run line of
the heater core
tubing. The heater core tubing passes through the fins and wherein U-shaped
returns are
provided on opposite exterior surfaces of the heater core body to connect the
parallel tubing
sections in a serpentine fashion within the interior space of the heater core.
The number of fins
and the total tubing length passing inside the heater core can be selected to
control the residual
time of water travelling through the heater core and the amount of heat
transferring directly from
the heater core tubing to the fins and then to the return air. In one
embodiment, the heater core
tubing and the fins are made from a highly conductive material, such as
copper, brass, or their
alloys.
A pneumatic resistance screen can be provided inside the heater core between
the fins
and the front opening to increase the efficiency of the heater core. The
pneumatic resistance
screen can reduce the velocity of the return air pulled into the suction port
of the blower to
increase the resistance and therefore heat transfer from the heater core
tubing and the fins to the
return air as it passes through the fins into the blower.
A three-way tee can bifurcate the line from the heater core to direct the
heated water to
the mixing valve and back to the radiator tank through the one-way valve and
the hot water
return line. In one example, if hot water is not being used, such as not
exiting the water outlet,
then the water will circulate back into the radiator tank. If some hot water
is used, then only the
remaining portion of hot water not leaving the hydro-furnace will be returned
to the tank. As hot
water leaves the hydro-furnace, water from the water supply can flow into the
water inlet to
replace the heated water leaving the hydro-furnace. Thus, the amount of water
held in the hydro-
furnace can remain relatively constant.
The ignition control box, which can house the DSI board, can comprise a
control box
base and a cover. The cover can be flush with the surface of the housing or
extend partially out
from the housing surface. Alternatively, the cover can remain inside the
housing. In one
embodiment, the electro-mechanical control system is similar to those found in
standard furnaces
and water heaters. The DSI board is a microprocessor based control board that
operates all
functions of the hydro-furnace and provides terminal connections for power,
such as +12V,
grounding, the gas control valve to open and shut off the gas to the burner,
ignition terminal for
the spark igniter to light the burner, a remote indicator (LGT) to provide
feedback on the hydro-
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furnace operation and possible faults, and a safety loop to verify that the
TECO and BECO are
not open. The LGT can provide feedback and alerts in the form of LEDs located
on the cover of
the ignition control box, a surface of the housing, or a control panel located
away from the
housing. Optionally, an audible alarm may be incorporated to provide alerts.
A DSI board provided herein can be a microprocessor based control board that
can
operate all the function of the hydro-furnace according to safety and
regulation standards and
provide connections and controls for a sufficiently voltage for activating the
ignition to the
burner, a ground connection, the control of the gas valve to open, shut off,
and the control of gas
flowing to the burner, remote indicate (LED) power to provide feedback on
operation of the
hydro-furnace and possible faults, and safety loop to verify that the TECO and
BECO
thermostats are not open, among others.
The power terminal of the DSI board can be connected to a DC power supply
source,
such as the battery power supply source of the RV via a power cable. The
grounding terminal
can be connected to a grounding cable to the RV to ground the circuit. The DSI
board and the
microprocessor in the DSI board of the hydro-furnace can accept different
voltages, such as 12
Volt DC to 24 Volt DC. Generally, 12 Volt DC can be produced by the on-board
power system
of the RV to power various auxiliary devices. The power can be tied or linked
to the ignition
system or supplied from a battery bank with fulltime power, as is well known
in the RV industry.
The battery bank that supplies fulltime power can be charged by the vehicle's
generator or by
plug-in AC power when the RV is plugged into an AC source.
In addition to the DC connector port discussed above. an I/0 connector port
can be used
to set control parameters for the controller. Like the DC connector port, the
I/0 connector port
can be a passage or bore through the housing having a plastic ferrule or liner
that allows one or
more cables to pass therethrough for connections between the electric system
of the water heater,
such as the microprocessor, and a control panel, which can be mounted remotely
from the hydro-
furnace, such as near the kitchen, bathroom, or the vehicle dashboard. Power
may be supplied to
the thermostats and sensors, such as the TECO, BECO, LTS, and HTS, through the
DSI board or
separately from the DC power source of the RV.
The ignition terminal can be provided for the ignitor high voltage wires,
which supply the
necessary power to ignition control electronics including the ignition control
spark to supply the
ignition source for the burner.
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The RTS can be connected to the DC power supply source, the relay (R), the
blower, the
thermostats and temperature sensors, and the pump.
Various functions of the hydro-furnace. such as set temperature, water flow
rate, and air
flow rate, may be controlled by the DSI board. The microprocessor in the DSI
board can act as a
gateway for receiving signals and data from the various sensors and is
programmed to control
operation of various components of the hydro-furnace based on the received
signals and data, as
further discussed below. For example, based on the temperature data received
from one of the
thermostats or probes, the microprocessor can send control signals to the gas
control valve to
modulate gas flow feeding the burner.
The controller or DSI board of the hydro-furnace can be connected to an
onboard fulltime
DC power supply of the RV and not dependent on the car ignition system. By
connecting to the
vehicle's fulltime power, the DSI board is always powered and various set
points using a control
panel and various parameters and data used by the microprocessor can be
maintained or saved.
In other examples, the DSI board is equipped with auxiliary memory that stores
set points and
parameters and can retain the information even when power is disconnected to
the DSI board.
When auxiliary memory is incorporated, the DSI board can be supplied with the
vehicle's
generator power.
The electronic control system can be similar to an electro-mechanical control
system,
except that an electronic control board is used to monitor the water
temperature using thermistors
instead of thermostats. In an example, the LTS and HTS of the electro-
mechanical control
system are respectively replaced by the thermistor probes Tin and Tout of the
electronic control
system. The Tin probe can be placed at the input of the heat exchanger and the
thermistor probe
Tout can be placed at the output of the heat exchanger downstream of the BECO.
The electronic
control system can further include a thermistor probe Ti located at the top of
the radiator tank
and a thermistor probe T2 located at the bottom of the radiator tank to
determine the state of
mixing of the water and, indirectly, the water heating function. In another
example, the Ti probe
can be located at the upstream end of the radiator tank and the T2 probe can
be located at the
downstream end of the radiator tank. The electronic control board can directly
activate the pump
and the blower based on precise values measured by thermistor probes Ti, T2,
Tin, Tout, which
can be directly connected to the electronic control board.
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The DSI board in the electronic control system is also similar to the
electromechanical
control system, except that the power terminal is now connected to the
electronic control board
instead of the thermostats and temperature sensors. The RTS can also be
connected directly to
the electronic control board. Thus, operations in the electronic control
system can be handled by
the electronic control board. More precisely, a microprocessor in the
electronic control board
can receive and send signals to power and control the components in the hydro-
furnace.
In the present embodiment, the heated water can be stored in a coil reservoir
instead of a
radiator tank. The coil reservoir can be a tubular structure that can extend
between opposite
sides of the radiator compartment in a serpentine fashion with U-shaped ends
connecting parallel
tubing sections extending in opposite directions within the interior space of
the plenum. The coil
reservoir can form a plurality of loops confined within the lower radiator
chamber of the radiator
compartment. Each of the plurality of loops can be spaced apart from each
other to allow return
air to be drawn outside the hydro-furnace from the lower return air vent
through each of the
loops or tubing sections. Return air in the Heat can be transferred from the
coil reservoir into the
return air inside the radiator compartment or lower radiator chamber before
being drawn through
the heater core into the blower. Thus, like the radiator tank, the coil
reservoir can pre-heat the
return air to improve heating efficiency of the hydro-furnace.
In still other examples, additional probes and/or sensors can be connected in-
line with the
various tubing and lines of the hydro-furnace in either system for sensing and
controlling or
regulating other flow functions in either the electro-mechanical system or the
electronic control
system. Other sensors such as pressure and flow sensors may be added for more
advanced
functions to improve performance, such as user selection of performance
parameters,
troubleshoot capabilities to identify various system failures, warnings to the
user of potential
failures, and remote control of all features from a panel or handheld unit or
via interact access.
The various connections can be threaded, welded, by mating flanges, or
combinations thereof. In
some examples, a threaded bore is provided on a side of a fitting, such as a
threaded socket or a
threaded thermowell, for receiving a probe, which can include a thermostat, a
flow sensor, or
other sensing devices. Optionally, welding may be used to connect the various
components and
tubing sections.
As available space can be limited in RVs, the present disclosure provides for
modularization of the components of the hydro-furnace system. For example, the
system can be
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generally separated into segmented sub-systems that can be stored or mounted
in spaced apart
configurations. In an example, the hydro-furnace system can be separated into
a water heater
module, a tank module, and a hydro-furnace module. The modules can be located
separately
from one another, such as spaced from one another in different segmented
structures, throughout
the RV, with necessary connections between them. In this way, the components
of the hydro-
furnace system can be installed in small spaces in the RV that already exist
and are relatively
easier to access without the need for designing a sufficiently large space for
a single unit system.
Additionally, the modularization can allow for modular sizing of components to
fit the needs of
the specific RV. For example, a larger RV may require a large storage tank or
blower. In some
examples, the hydro-furnace system can be separated into two or more sub-
systems that can be
mounted in spaced apart configurations.
The separation of the components can provide a benefit for better isolation of
the water
heater unit and the exhaust system, which can produce emissions byproducts
from the burner that
can be harmful if introduced into the interior of the RV. The other benefit,
as previously
.. described, is the flexibility of storing sub-components or sub-systems in
multiple smaller spaces
throughout the RV instead of a single large space.
The hydro-furnace system can have a water heater module that contains a water
heater or
water boiler. The water heater can be controlled by an electronic control
board acting in
response to a thermostat that monitors the water temperature using thermistor
probes. The
electronic control system can use a DSI board to control the water heater.
The room thermostat can generate a heat request for space heating as desired
by a user.
The electronic control board can receive the heat request from the room
thermostat and control
the components of the hydro-furnace system as necessary to provide the
requested heat.
The electronic control board, though the DSI board, can control a burner in
the water
heater module. The water heater module can receive water from a cold water
source or from the
storage tank. In an initial state, the system is primed with water from the
cold water source.
The water input into the water heater module can be heated and then either
supplied as
warm water through a warm water line to the user or as heated water through
the hydro-furnace
water circuit to provide heat to the RV.
From the water heater module, the heated water can flow through the hydro-
furnace
water circuit to the hydro-furnace module. There, the heated water can flow
through a heat
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exchanger. A blower can move air across the heat exchanger to heat the air
from heat transferred
from the heated water. The blower can be controlled by the electronic control
board. The heated
air can then be distributed to the interior of the RV through the air vents of
the hydro-furnace
module. To improve the efficiency of the hydro-furnace module, there can be
provided a
pneumatic resistance screen in front of the heat exchanger. This can increase
the efficiency of
the heat exchanger by increasing the residual contact time with the heat
exchanger, such as by
reducing the velocity of the air being moved by the blower.
After circulating through the heat exchanger of the hydro-furnace module, the
heated
water flows to the tank module. There, the heated water flows through a one-
way valve before
flowing into the tank through a manifold. Water from the tank can then be
recirculated to the
water heater module through a downstream one-way valve by way of a pump and a
solenoid
valve. The pump can actively circulate the water through the water heater
module until the
temperature of the storage tank reaches a desired temperature. The temperature
can be checked
by way of a temperature probe downstream of the storage tank. The electronic
control board can
control the pump, solenoid valve, and blower based upon the readings from the
thermostat and
the temperature probe.
The use of the one-way valves, prevent mixing of water in the different phases
of the
heating loop. Upon the water of the storage tank reaching the desired
temperature, the electronic
control board can shut off the burner of the water heater module.
As scalding is based on both temperature and duration of contact, the present
disclosure
provides for a mechanism to prevent the risk of scalding to the user. The
water heater module
can be designed to provide a predetermined amount of maximum heating to the
water. In this
way, the maximum temperature of water heated from the cold water source can be
limited to
prevent scalding of a user when delivered for use through the water outlet.
To increase the heat of the water of the heating loop of the hydro-furnace
system, the
water from the heating loop can be continually cycled to water heater module
and heated. In this
way, the water can be heated to a higher temperature than that of the water
delivered to the user.
Additionally, the heated water of the hydro-furnace system can be cut-off to
the user by
means of both the pump and the solenoid valve. Use of the solenoid valve
allows for quick shut
off of the flow of water from the stored water from flowing to the water
heater. In this way,
stored water that is hot is prevented from flowing into the water heater and
being output to the
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customer. As a result of the shut off of flow from the stored water, the
temperature of the water
input into the water heater is limited by the inflow of cold water. The
resulting heating of the
water by the water heater is thereby limited in terms of the temperature of
the water that can
output to the user through the water outlet.
Furthermore an emergency cutoff (ECO) can be applied to the water outlet for
preventing
the temperature of the water for a user from being improperly high even in the
case of a
malfunction.
In addition to the singular hydro-furnace module, there can be additional
hydro-furnace
modules installed in the RV to provide zone specific heating as desired.
Embodiments of the water heater utilize a gas burner. However, it can also be
envisioned
that an electric water heater can also be used, which uses resistance heating
coils or ceramic
heating coils.
Additionally, the hydro-furnace system can use alternative control systems,
such as
electro-mechanic al.
The water heater module incorporates a burner configured to heat water. The
water
heater module has a water input for receiving cold water or circulating water
from the hydro-
furnace heating loop. The water input may include a manual water shut off
valve. The water
input may be on a first side of the housing.
A fuel or gas inlet for introducing fuel to the burner in the water heater
module can
extend out from the first side of the housing. A fuel or gas line can be
connected to the gas inlet
to supply fuel, such as propane, to the burner. The gas inlet can be a male
connector, however,
the gas inlet may be a female connector extending into the housing, in which
case a gas line
having a male connector tip can engage the female connector to supply fuel to
the burner.
Pressure fittings may also be used to connect the various lines and components
of the hydr0-
furance system.
The water input can be coupled to a heat exchanger tubing as further
illustrated. The heat
exchanger tubing can wrap around the exterior of a heat exchanger, which can
be a conductive
body having a skirt or a plenum. The plenum and the heat exchanger tubing can
be made of a
conductive material, such as aluminum, copper, copper alloy, brass, alloys, or
other metals.
The plenum and the heat exchanger tubing can be made from other corrosive
resistant
materials that are able to withstand the direct or indirect heat of the
burner, or be plated or coated
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with a corrosive resistant material. The heat exchanger tubing can wrap around
the plenum from
a bottom end of the plenum towards a top end of the plenum, elevation-wise,
and by conduction
is heated by the plenum which then heats the water running through the heat
exchanger tubing.
This can be understood as being similar to a preheat. Because both the plenum
and the heat
exchanger tubing can be made from a conductive material, heat energy is
transferred by
conduction from the plenum to the heat exchanger tubing and from the heat
exchanger tubing to
the water running therein. As a result, the water running around the heat
exchanger is pre-heated
before entering the heat exchanger. The heat exchanger tubing then enters the
heat exchanger so
as to be heated by the heated gas from the burner, as further discussed below.
The plenum can have an opening extending from the bottom end to the top end.
Within
the plenum of the heat exchanger, a plurality of spaced apart internal fins
can be located in the
opening between the bottom end and the top end to provide additional heat
transfer paths. In one
example, the internal fins are located near the top end to provide space for
the burner. The
internal fins can be closely spaced or loosely spaced inside the plenum to
form baffles or
channels for the flow of heated air from the bottom end of the heat exchanger
and then rising
through the internal fins and out the top of the heat exchanger, elevation-
wise.
The number of internal fins and the surface area of each of the internal fins
can depend
on the desired heat exchange rate by convection, conduction, and radiation
exchanging with the
interior run line of the heat exchanger tubing. The heat exchanger tubing
passes through the
internal fins and wherein U-shaped returns are provided on outer surfaces on
opposite sides of
the plenum to connect the parallel tubing sections in a serpentine fashion
within the interior
space of the plenum. Thus, the heating pipe can form continuous passes through
the opposite
sides of the plenum and the internal fins to maximize the heat transfer from
the internal fins to
the heat exchanger tubing to heat the water flowing therein. The number of
fins and the total
tubing length passing inside the plenum can be selected to control the
residual time of water
travelling through the plenum and the amount of heat transferring directly
from the burner to the
plenum and from the burner to the fins and then to the heat exchanger tubing.
The water heated through the heat exchanger tubing can then output through
water output
for delivery to the user or the hydro-furnace heating loop.
An electrical connector can be provided on the first side of the house also
for connection
of the electronics housed in the water heater module. The electrical connector
may be a quick
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disconnect type. The electrical connector may be a plurality of connectors for
different power
and signal connections.
An exhaust system comprising an exhaust conduit or duct can be provided to
collect
exhaust fumes rising from the burner and direct the exhaust fumes and away
from and outside
the water heater module through the burner outlet vent. The exhaust system can
be positioned at
the top of the plenum and coupled directly to the top end of the plenum. The
exhaust system can
extend horizontally towards the burner outlet vent. The exhaust system can
have a larger
opening at the output end to provide an open flow path to the burner outlet
vent for the
combustion byproducts.
The exhaust system can be sealed to ensure the combustion byproducts flow
directly out
the burner outlet vent. An exhaust fan powered by an exhaust fan motor may
also be provided to
assist directing the exhaust fumes through the burner outlet vent. The exhaust
fan may be
connected to a microprocessor of a controller such as the DSI board explained.
The DSI board
can operate the exhaust fan motor to turn the exhaust fan on and off based on
signals sent to the
microprocessor from one or more sensors.
Additional ducting may be provided to direct the exhaust gas through the
burner outlet
vent and out, such as out an opening to an exterior of the mobile or
recreational vehicle. In some
examples, an induced draft fan, a force draft fan, or both can be incorporated
to move gas
through the hydro-furnace.
Embodiments of the tank module can have a water storage tank, an upstream one
way
valve, a downstream one way valve, a pump, and a solenoid valve. The tank
module can contain
only some of the components of the storage tank, the upstream one way valve,
the downstream
one way valve, the pump, and the solenoid valve. It is possible to place the
upstream one way
valve, the downstream one way valve, the pump, and the solenoid valve in
locations along the
system between the water heater module, the tank module, and the hydro-furnace
module.
The storage tank can store hot water for the hydro-furnace water circuit. The
storage tank
can be an expansion tank and contain a resilient bladder certified for the
operating temperature
and pressure. The expansion tank can protect the RV water system from
excessive pressure. The
tank can be partially filled with air, the compressibility of which absorbs
excess water pressure
.. and/or water volume.
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The storage tank may be cylindrical in shape. The storage tank may be oriented
in an
upright position, with an opening at one of the end surfaces of the
cylindrical shape, the end
surface considered the downward oriented face when installed in an RV.
The storage tank can have an alternative shape, such as rectangular,
trapezoidal, or
spherical. Also, the storage tank can be oriented in different directions,
such as having the
cylindrical shape be oriented on its side.
The opening of the storage tank is coupled to a manifold. The manifold can
include an
input side connected to a tube. The tube can convey the water from the input
side to an upper
portion of the storage tank. The manifold can allow for water to exit the
storage tank at the
bottom of the storage tank at the opening. In this way, the tank can have
heated water conveyed
to the top portion while relatively cooler, denser water at the bottom of the
storage tank can be
drawn.
The manifold can include a chamber area for the output side. The chamber area
can
connect to the downstream section of the piping of the system.
The manifold can be coupled to the storage tank by way of corresponding
threading. The
coupling can also be achieved by way of corresponding lugs and grooves on the
components.
The coupling can also be achieved by way of a slip fit, and can also utilize a
clamping ring over
the slip fit.
The manifold can be on the bottom surface of the storage tank. However, the
manifold
could be attached to side surfaces of the storage tank instead of the bottom
surface. The
manifold can be attached to a lower portion of a side surface near the bottom
portion of the
storage tank.
The manifold can be a single connection point for both the input side and
outside side.
Additionally, the manifold can also be achieved with two connection points.
The input side can
be separated from the output side. Instead of a single connection point, the
input side can be
attached to a second opening of the storage tank. In such a case, the opening
for the input side
can be provided where convenient. The input side in such a case can utilize a
tube as necessary
to convey water to the upper portion of the storage tank.
Alternatively, the opening may be provided at an upper portion of the storage
tank. such
that a tube is not necessary. Combinations of such a split connection could
have the input side
and the output side located on different surfaces of the storage tank.
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The connections to the storage tank can be arranged as necessary to fit the
installation
layout of the RV. An installation can have the routing of pipe connecting the
components
resulting in a U-shape underneath the storage tank to minimize a footprint of
the components for
compactness. In this case, the upstream one way valve can be in line with the
manifold. The
routing can then go through a 90 degree bend to the downstream one-way valve.
After the
downstream one-way valve, the routing can then go through another 90 degree
bend to the pump
and the solenoid valve. Alterative bend configurations may be used as
necessary to provide the
convenient routing and attachment to the tank module when installed in the RV.
The upstream one way valve, by only allowing flow in a direction from the
hydro-furnace
module to the tank module, prevents the potential mixing of water stored in
the tank back to the
water used for heating with the hydro-furnace module.
Downstream of the manifold, there is the downstream one way valve coupled in
line with
the pump, and the solenoid valve. The downstream one way valve can prevent
flow of water
back into the storage tank and mixing from downstream. The pump can be powered
to pump
water from the storage tank back to the water heater module.
To minimize the risk of hot water being released, the solenoid valve can be
used to
control the flow of water from tank module back to the water heater module.
The solenoid valve
can be used to provide a quick shut off mechanism to prevent flow of hot water
stored in the
storage tank. For safety, the solenoid valve can be of a type that is closed,
or prevents flow, in an
unpowered state. or off state. In this way, if there is a power loss to the
solenoid valve, the
hydro-furnace water circuit is cut-off from providing hot water back to the
water heater module.
The tank module can have a housing to house the components of the tank module.
The
housing may house just the tank. The housing may house some or all of the
storage tank, the
upstream one way valve, the downstream one way valve, the pump, and the
solenoid valve. The
housing can be shaped to substantially correspond to the storage tank. The
housing can be
shaped to correspond to a space in the RV or mobile vehicle. The components of
the tank
module can be retained inside the housing by being sized to fit or by
retention methods such as
mounting brackets. It is not necessary that each and every component be
retained, but only that
sufficient constraining is provided to minimize excess force from acting on
the components. The
use of a housing can allow for fitment inside the RV while using off-the-shelf
components,
which may be sized or shaped differently. For example, the expansion tank can
be an off-the-
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shelf item that can be easily procured for different installation types. In
this way, the mere
change in dimensions for the house is much simpler and cheaper than attempting
to custom
design storage tanks for different installations.
The hydro-furnace module can include a blower, a heat exchanger, and a
pneumatic
resistance screen. Other components or elements may be included with the hydro-
furnace
module, such as fittings, brackets, sensors, etc.
The hydro-furnace module can further include a housing to house the components
of the
hydro-furnace module. The housing can provide air vents to route the heated
air into the interior
of the RV.
The hydro-furnace module can receive heated water from the water heater module
and
route the heated water through the heat exchanger. The heat exchanger
transfers heat from the
water to the air of the hydro-furnace module, such that heated return air can
be supplied by the
blower. The heat exchanger can comprise a core body with a box-like shape and
core tubing.
In embodiments, the blower can have a suction portion and a blower port to
move the air.
Alternatively, the ports can be reversed, or a different type of blower can be
used, as desired.
Within the core body of the heat exchanger, a plurality of spaced apart fins
can be
provided. The fins can be closely spaced or loosely spaced inside the core
body to form baffles
or channels for the flow of air through the heat exchanger generated by the
moving of air by the
blower. The number of fins can depend on the desired heat exchange rate by
convection,
conduction, and radiation exchanging with the interior run line of the core
tubing.
The core tubing passes through the fins and wherein U-shaped returns are
provided on
opposite exterior surfaces of the core body to connect the parallel tubing
sections in a serpentine
fashion within the interior space of the heat exchanger. The number of fins
and the total tubing
length passing inside the heat exchanger can be selected to control the
residual time of water
travelling through the heat exchanger and the amount of heat transferring
directly from the core
tubing to the fins and then to the air.
In one embodiment, the core tubing and the fins, are made from a highly
conductive
material, such as copper, brass, or their alloys.
In this way, the blower can move air over the heat exchanger to transfer the
heat from the
water to the air of the hydro-furnace module. The heated air can then be
provided through air
vents from the housing of the hydro-furnace module to the interior of the RV.
The air vents can
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be provided to the housing such that there is necessarily some circulation of
heated air inside the
housing of the hydro-furnace module as the blower operates. As such, the
temperature of the air
inside the house can be higher than ambient.
The present disclosure provides a modular RV water heating and furnace system
having a
heat exchanger housing that houses a heat exchanger and a burner, a hydro-
furnace housing that
houses a heater core and a blower, and a tank housing that houses a storage
tank.
The burner provides heat to the heat exchanger and the heat exchanger heats
water
flowing therethrough it.
The blower moves air through the heater core, which is provided with the
heated water
from the heat exchanger.
The present disclosure provides a modular RV water heating and furnace system
having a
water heater, a heat exchanger, and a storage tank. The water heater heats
input water and
outputs the heated water. The heated water is then provided to the heat
exchanger. The heat
exchanger attached to a blower, which moves air through the heat exchanger,
thereby warming
the air. The heated water is then provided through a one-way valve from the
heat exchanger to a
storage tank. The heated water is then provided from a second one-way valve to
a pump and a
solenoid valve for circulation back to the water heater.
Methods of making the hydro-furnace systems, of using the hydro-furnace
systems, and
of installing the hydro-furnace systems as described herein are within the
scope of the present
invention.
Brief Description of the Drawings
These and other features and advantages of the present devices, systems, and
methods
will become appreciated as the same becomes better understood with reference
to the
specification, claims and appended drawings wherein:
FIG. 1 shows a perspective view of an embodiment of a combination water and
air
heating system for an RV;
FIG. 2 shows an exploded perspective view of the combination water and air
heating
system of FIG. 1;
FIG. 3 shows a perspective view of the combination water and air heating
system of FIG.
1 shown without panels to expose the various internal components of the water
heater;
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FIG. 4 shows a perspective view of the combination water and air heating
system of FIG.
3, but shown from a different aspect;
FIG. 5 shows a perspective view of the combination water and air heating
system of FIG.
3, but shown from another different aspect;
FIGs. 6A and 6B show a front view and a bottom view of the combination water
and air
heating system of FIG. 1;
FIG. 7 shows a schematic diagram of the combination water and air heating
system of
FIG. 1, illustrating one embodiment of the principles of operation.
FIG. 8 shows a schematic diagram of one embodiment of the combination water
and air
heating system utilizing an electromechanical control system;
FIG. 9 shows a schematic diagram of one embodiment of the combination water
and air
heating system utilizing an electronic control system; and
FIG. 10 shows a perspective view of another embodiment of a combination water
and air
heating system for an RV with a coil reservoir tank.
FIG. 11 shows a schematic layout for a modularized hydro-furnace system 100
using an
electronic control system.
FIG. 12 shows a side view of exemplary implementations of the different sub-
systems of
FIG. 11.
FIG. 13 shows a perspective view of exemplary implementations of the different
sub-
systems of FIG. 11.
FIG. 14 shows a perspective view of an arrangement of a tank module with a
storage tank
and flow control components.
FIG. 15 shows a perspective view of an arrangement of a blower and heat
exchanger for
providing heated air to an RV.
Detailed Description
The detailed description set forth below in connection with the appended
drawings is
intended as a description of the presently preferred embodiments of a
combination water and air
heating system for a recreational vehicle (RV) provided in accordance with
aspects of the present
assemblies, systems, and methods and is not intended to represent the only
forms in which the
present devices, systems, and methods may be constructed or utilized. The
description sets forth
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the features and the steps for constructing and using embodiments of the
present assemblies,
systems, and methods in connection with the illustrated embodiments. It is to
be understood,
however, that the same or equivalent functions and structures may be
accomplished by different
embodiments that are also intended to be encompassed within the scope of the
present
disclosure. As denoted elsewhere herein, like element numbers are intended to
indicate like or
similar elements or features.
With reference now to FIG. 1, a perspective view of a combination water and
air heating
system or -hydro-furnace" 100 for a mobile vehicle, which can include a
recreational vehicle
(RV), a boat, a mobile home trailer or fifth wheel, provided in accordance
with aspects of the
present disclosure is shown. The hydro-furnace 100 can function as both a
water heater and a
space heater by supplying both hot water and hot air through three basic
systems: a boiler
system, a recirculating system, and a radiator system. Heated water and heated
air can be
generated concurrently or serially. Generally speaking, the boiler system can
provide a heat
source for water running therethrough by combusting air and fuel, such as
propane, and
exhausting combustion products to provide on-demand hot water and hot water
for a storage
tank.
Because fuel and byproducts of fuel are involved, the boiler system can be
sealed off
from the recirculating system and the radiator system to prevent combustion
byproducts and
unused fuel from entering the RV and potentially circulating harmful gas
throughout the mobile
vehicle. For purposes of the following disclosure, reference is made to an RV
although other
mobile vehicles can use the hydro-furnace of the present disclosure.
To increase the temperature inside the RV, the recirculating system can heat
return air
drawn from inside the RV using the water heated in the boiler system as the
heat source, and
deliver the heated air back inside the RV. The radiator system can store
heated water and heat
the return air when hot air is desired. As described in further detail below,
the boiler system can
include gas and electrical controls, a burner, a heat exchanger, a water pump,
water tubing and
connections, and an exhaust system. The recirculating system can include a
blower, a heater
core, a return air port, and water tubing and connections. The radiator system
can include a
radiator tank, an air plenum and duct ports, and water tubing and connections.
However,
.. components of the three systems can be re-arranged within the housing of
the hydro-furnace
without deviating from the scope of the invention.
Each of the three systems can be contained within one or more chambers or
compat __ intents
within a housing 102. The components contained in the housing 102 can include
gas lines, water
lines, sensors, switches, mechanical and electromechanical components, and
electronics for
controlling the flow and operation of both the fuel and water flowing into
and/or through the
hydro-furnace 100. Note that a hydro-furnace for an RV, such as the hydro-
furnace 100 disclosed
herein, is different from a portable water heater and a portable room heater,
which is understood
to be portable but not necessarily for the heavy duty use and more rigid
requirements for RVs.
The housing 102 can comprise a plurality of removable panels mounted together
to form
two or more sides of the hydro-furnace 100 and enclose the various components
inside the hydro-
furnace 100. Any number of panels and sub-panels can be included to form the
outer surface of
the hydro-furnace 100 and divide an interior of the housing 102 into separate
smaller housings
or compattments to house components of each of the three systems. In some
examples, one or
more of the panels of the housing can be permanent or non-removable from a
housing frame.
In the illustrated embodiment, the housing 102 can be divided into a radiator
compat ttnent
102a at a back side or second side 101b of the hydro-furnace 100 and a main
compattment 80 at
a front side or first side 101a of the hydro-furnace 100. The main compattment
80 can be further
divided into a blower compattment 102b and a burner compat
_____________________ intent 102c. As shown, the burner
compattment 102c is located on a left side 101c of the hydro-furnace 100, from
the perspective
of the first side 101a looking at the second side 101b and the blower
compartment 102b is located
on a right side 101d of the hydro-furnace 100.
In another embodiment, the burner compat
_______________________________________ intent 102c is located on the right
side 101d of
the hydro-furnace 100 and the blower compattment 102b is located on a left
side 101c of the
hydro-furnace 100. Said differently, the burner compattment 102c and the
blower compat ttnent
102b can be located along a first side or a front side 101a of the housing
102, and the radiator
compattment 102a can be located along a second side or a back side 101b of the
housing 102
directly opposite the first side. The components of the radiator system, the
recirculating system,
and the burner system can cooperate by extending through the interior sections
of the housing
102, better illustrated in reference to FIG. 2.
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For purposes of the following discussions, the first side or front side 101a
of the housing
102 shown in FIG. 1 can also be considered the front of the hydro-furnace 100,
and the second
side or back side 101b of the housing 102 can be considered the back of the
hydro-furnace 100.
One of ordinary skill in the art will recognize that these directional
assignments to the
components of the housing 102 and the hydro-furnace 100 are for purposes of
description only as
the hydro-furnace 100 may be installed in any orientation that allows for
proper operation.
The housing 102 includes vents, input and output connectors, and interface
ports for
connecting the hydro-furnace 100 to the RV. A burner inlet vent 103 for
introducing air outside
of the housing 102 into the burner compartment 102c is shown located at the
front side of the
housing 102. A burner outlet vent 105 for channeling combustion byproducts of
a burner 275 for
heating a heat exchanger 250, unburned fuel, and other gases outside the
burner compartment
102c is shown located above the burner inlet vent 103 at the front side of the
housing 102. Thus,
the burner inlet vent 103 and the burner outlet vent 105 are provided on a
front side of the hydro-
furnace 100. The burner compartment 102c can be sealed off from the other
compartments to
prevent the combustion byproducts of the burner 275, unburned fuel, and other
gases inside the
burner compartment 102c from entering the blower compartment 102b and the
radiator
compartment 102a of the housing 102 and mixing with the heated air to be
delivered inside the
RV. For example, ducting can be connected to the burner outlet vent 105 to
direct the exhaust
gas to the exterior of the RV.
A fuel or gas inlet 104 (FIG. 4) for introducing fuel to the burner 275 in the
burner
compartment 102c is shown extending out from a third side or left side of the
housing 102.
Alternatively, the gas inlet 104 can be located on a front side of the housing
102. In another
embodiment, the gas inlet 104 is located on a right side of the housing 102,
depending on the
location of the burner compartment 102c within the housing 102. Again, the
orientation of the
various components relative to the housing is not crucial and can vary without
deviating from the
scope of the present invention.
A fuel or gas line can be connected to the gas inlet 104 to supply fuel, such
as propane, to
the burner 275. As shown, the gas inlet 104 is a male connector but a female
connector can
optionally be used, in which case a gas line having a male connector tip can
engage the female
connector to supply fuel to the hydro-furnace 100. A gas tubing or line can be
provided to
connect the gas inlet 104 to a gas control valve 278, which can be connected
in line to a burner
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275 to control gas flow from a gas source through the burner of the hydro-
furnace 100. Other
valves, such as linear or equal percentage valves, are contemplated for use
with the present
system to regulate gas flow through the hydro-furnace.
Control of the gas control valve 278 can be based on various sensed
parameters, such as
water flow, inlet and/or outlet water temperatures, and set point. In one
embodiment, the gas
control valve 278 is a linear valve. In an example, the linear valve is
provided by CAE, model
number CPV-H2467AY, which can be used to control gas flow through the hydro-
furnace 100.
An additional valve in line with the gas control valve 278 may be used to
further control gas
flow, function as an emergency shut off valve, or any desired function. The
additional valve can
.. be an on/off solenoid valve that can function as an emergency shut off
valve and that can receive
operating signals from an emergency cut off switch (ECU), which can be a hi-
metallic switch.
The gas control valve 278 can be connected to a microprocessor of a
controller, which
can be programmed to control the gas control valve 278 based on data and
signals received from
sensors such as thermostats or therrnistor probes. In general, the gas control
valve 278 can be an
on/off valve with a high/low setting. Alternatively, an additional valve can
be an on/off valve
and the gas control valve 278 can be regulated to control gas flow from a high
setting to a low
setting, as described in further detail below. Together, the gas control valve
278 and the
additional valve may also act as a dual emergency shut off valve when both are
in the off
position. In one example, the hydro-furnace 100 may accept propane gas only,
such as while
.. travelling with propane tanks or when parked at a camp site. In another
example, the hydro-
furnace 100 may accept another type of fuel that can be supplied through the
gas inlet valve 104,
such as a gas source at a camp site.
A DC connector port for powering the hydro-furnace 100 can be located adjacent
the gas
inlet valve 104. In an example, the DC connector port is a passage or bore
through the housing
.. 102 having a plastic ferrule or liner that allows one or more cables to
pass therethrough for
connections between the electric system of the hydro-furnace 100, including
the controller or
DSI board inside or adjacent to an ignition control box 280 discussed in
detail below, and the
vehicle's electric system.
A water inlet 106 (FIG. 3) for introducing water from a water supply into the
radiator
compartment 102a is shown extending out from a fourth side or right side 101d
of the housing
102 opposite the left side 101c of the housing 102. Alternatively, the water
inlet 106 can be
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installed extending from the same side but from the blower compartment 102b. A
water outlet
108 for delivering heated water out from the hydro-furnace 100 is also shown
extending out from
the fourth side or right side 101d of the housing 102 adjacent to the water
inlet 106. The water
inlet 106 and the water outlet 108 can be mounted side-by-side or one above
another elevation-
wise. The location of the water inlet 106 and the water outlet 108 is not
limited, and can also be
located on other sides of the housing 102 or separately on different sides of
the housing 102.
A voltage connector port for powering the hydro-furnace 100 can be located
adjacent the
gas control valve 278 or at some other accessible location within the housing
102. In an
example, the voltage connector port can be a DC connector port. The DC
connector port can be
.. a passage or bore extending through the housing having a plastic ferrule or
plastic liner that
allows one or more cables to pass therethrough for connections between the
electric system of
the water heater, such as the controller, and the vehicle's electric system.
The voltage connector
port may also be sealed air-tight to prevent gases in the burner chamber 102c
from leaking out
other than the burner outlet vent 105.
A first or upper return air vent 107 (FIGs. 1 and 2) and a second or lower
return air vent
109 can extend through the second or back side 101b of the housing 102 to
allow return air
outside the housing 102 to be pulled into the blower compartment 102b of the
hydro-furnace 100
through the radiator compartment 102a. A heater core 300 located in the blower
compartment
102c by a blower 325 is provided for heating the return air. A filter, such as
a HEPA filter or
.. other high efficiency filters, can be provided at the upper return air vent
107, the lower return air
vent 109, or both vents 107, 109, so that the return air can be filtered
before it is heated and
delivered. This can also ensure cleanliness of the components in the system.
The filter can be
installed inside or outside of the housing 102. If installed outside the
housing 102, the filter can
be easily attached and detached easily from the hydro-furnace 100 for cleaning
or replacement,
such as in a cartridge compartment attached to the housing.
FIG. 2 shows an exploded view of the housing 102 of the hydro-furnace 100 to
better
illustrate how the components can be assembled inside the compartments formed
by the panels
of the housing 102. The radiator compartment 102a can be rectangular shaped
and formed from
a C-shaped radiator housing panel 110 having a central panel and two subpanels
extending from
opposite edges of the central panel. A left side radiator housing panel 112
and a right side
radiator housing panel 114 can attach to the ends of the central panel and the
two subpanels of
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the C-shaped radiator housing panel 110. A radiator housing door 116, which
comprises air
vents 107, 109, can attach to the remaining free ends of the two subpanels of
the C-shaped
radiator housing panel 110 to cover the opening opposite the central panel of
the C-shaped
radiator housing panel 110.
The upper return air vent 107 and the lower return air vent 109 are located on
the radiator
housing door 116. Thus, the radiator housing door 116 can also be the back
side 101b of the
housing 102. An optional radiator housing divider 118 can be positioned inside
the radiator
compartment 102a to subdivide the radiator compartment 102a into separate
smaller
compartments. As shown in FIG. 1, the radiator housing divider 118 can extend
from the central
panel of the C-shaped radiator housing panel 110 to the radiator housing door
116 between the
upper return air vent 107 and the lower return air vent 109 to divide the
radiator compartment
102a into an upper radiator chamber 111 and a lower radiator chamber 113.
Thus, return air can
be drawn into the upper radiator chamber 111 through the upper return air vent
107 and return air
can be drawn into the lower radiator chamber 113 through the lower return air
vent 109. The
lower radiator chamber 113 can house a radiator tank 200 to preheat the return
air as further
discussed below.
Adjacent the radiator compartment 102a is the main compartment 80, which can
polygonal shape, such as a rectangular shape, and formed from a C-shaped main
housing panel
120 having a central panel and two subpanels extending from opposite edges of
the central panel.
A left side main housing panel 122 and a right side main housing panel 124
covering the ends of
the C-shaped main housing panel 120 or, more specifically, attached to the
ends of the central
panel to form an enclosure. The two subpanels of the C-shaped main housing
panel 120 and a
radiator housing door 116 are attached to the remaining free ends of the two
subpanels of the
main housing panel 120 to cover the opening of the C-shaped main housing panel
120 opposite
the central panel of the C-shaped main housing panel 120.
A main housing divider 128 can be positioned inside the main compartment to
subdivide
the main compartment into the blower compartment 102b and the burner
compartment 102c. As
shown in FIG. 1, the main housing divider 128 can extend between the
subpanels, the central
panel of the C-shaped main housing panel 120, and the main housing door 126 to
divide the main
.. compartment into a left compartment or the burner compartment 102c and a
right compartment
or the blower compartment 102b.
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The burner inlet vent 103 and the burner outlet vent 105 for providing
ventilation for only
the burner compartment 102c can be located on the main housing door 126. Thus,
the main
housing door 116 can be the first or front side 102a of the housing 102. The
main housing
divider 128 can be provided to effectively seal the burner compartment 102c
from the blower
compartment 102b to prevent fuel and combustion by products from entering into
the blower
compartment 102b.
Air passages and water lines or tubing can extend between the radiator
compartment
102a, the adjacent blower compartment 102b, and the adjacent burner
compartment 102c through
one or more cutouts defined in both of the central panels of the C-shaped
radiator housing panel
110, the C-shaped main housing panel 110, and the main housing divider 128.
The various
cutouts between the central panels and other internal panels allow the
components, such as
cables, wires, tubing, lines, fittings, brackets, electronics, fans, etc.,
from each system to connect
to another system. Any cutouts between the burner compartment 102c and any
other
compartment to allow components to extend therethrough can be sealed with
components
extending therethrough to prevent gases from leaking into the blower
compartment 102b or the
radiator compartment 102a. Optionally, sealants, fire retardant fabric or
cloth, or other paneling
means for isolating the different compartments can be used.
The cutouts between adjacent compartments can be similarly shaped and aligned
to each
other. In one example, an upper first cutout 111, a second cutout 113 below
the upper first
.. cutout 111, and a lower third cutout 115 below the second cutout 113 of the
central panel of the
C-shaped radiator housing panel 110 can align with similarly shaped cutouts on
the main housing
panel 120. In an example, the first cutout can be rectangular, the second
cutout can be circular,
and the third cutout can be rectangular. The cutouts on the main housing panel
120 therefore
include an upper rectangular cutout or first cutout 121, a second cutout or a
circular cutout 123
below the upper rectangular cutout 121, and a third cutout or a lower
rectangular cutout 125
below the circular cutout 123 of the central panel of the C-shaped main
housing panel 120.
Alternatively, a single panel can divide the radiator compartment 102a from
the main
compartment so that alignment of cutouts from different panels is not
necessary. The function of
each of the compartments of the housing 102 and how each relate to the other
can be elaborated
further with details of the components inside the housing 102 with reference
to FIGs. 3-6.
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Referring to the schematic flow diagram shown in FIG. 7, a general overview of
the
principles and operations of the hydro-furnace 100 is shown. When hot water
and/or hot air is
desired, the hydro-furnace 100 can be powered on to activate the electrical
and electro-
mechanical components of the system. If water is not already present in the
hydro-furnace 100,
water can be directed from a water supply (not shown) through the water inlet
106 into a radiator
tank 200 located in the radiator compartment 102a and to a mixing valve 150
located in the
blower compartment 102c. Water line pressure or from a pump can move the water
through the
system.
Initially, the temperature of the water in the radiator tank 200 may be at or
near the
temperature of the inlet water flowing through the water inlet 106.
Eventually, the temperature
of the water in the radiator tank 200 will increase as it circulates through
the hydro-furnace 100,
as discussed further below. The radiator tank 200 is configured to store the
heated water and
transfer heat from the stored heated water to the return air flowing past the
radiator tank 200
when the blower 325 is on to heat the return air as discussed further below.
The mixing valve
150 can regulate fluid flow between heated water leaving the heater core 300
and water from the
water inlet 106. That is, the mixing valve 150 can mix the water at the two
different
temperatures from the two different sources to achieve a desired downstream or
outlet water
temperature of the water exiting the hot water outlet 108. Said differently,
the mixing valve 150
can mix the water from the water inlet 106 with the heated water from the
heater core 300 to
provide hot water at the desired outlet water temperature.
In one example, the desired outlet water temperature of the hot water leaving
the hydro-
furnace 100 through the hot water outlet 108 can be 120 degrees F. Thus, the
mixing valve 150
has two inputs and one output. The mixing valve 150 can be a manually operable
control valve
or an electronically adjustable control valve. The outlet water temperature
can be adjusted by
controlling the mixing valve 150. In one embodiment, a microprocessor of a
controller can send
signals to adjust the mixing valve 150 to produce a desired outlet water
temperature using
feedback from a temperature sensor located at or near the hot water outlet
108.
Before hot water can be dispensed from the hot water outlet 108, the water
inside the
radiator tank 200 can be heated to an acceptable temperature. To do so, the
water can be
circulated from the radiator tank 200 by a pump 170, to a heat exchanger 250
where the water is
heated by a burner 275. The heat exchanger 250 can be heated directly or
indirectly by a burner
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275 located in the burner compartment 102c. The burner 275 can burn fuel fed
from the gas inlet
104 to produce combustion gases to heat the water in the heat exchanger 250.
In one example,
the fuel is liquefied petroleum (LP) gas or propane. The heat exchanger 250
can transfer heat
from the combustion gases to the water.
From the heat exchanger 250. the water is pumped to a heater core 300. At
least some of
the heat from the heated water in the heater core 300 can be drawn or pulled
by a blower 325
when powered on to provide heated air. The blower 325 can heat return air in
the RV by pulling
the return air past the radiator tank 200 and through the heater core 300
before delivering the
heated air to an air plenum 340 (FIG. 7) and back to the RV through heating
ducts 345. Return
air drawn through the lower return vent 109 passing over the radiator tank 200
can also transfer
heat by convection to the surrounding return air. More specifically, when a
heat request is
generated by a room thermostat (RTS) 360 (FIGs. 8 and 9) for space heating,
the blower 325 can
turn on to pull return air from the upper and lower radiator chambers of the
radiator compartment
102a through the heater core 300 to supply heated air to an air plenum 340
located in the radiator
compartment 102a or blower compartment 102b.
The air plenum 340 is connected to heating ducts 345 extending outside the
hydro-
furnace 100. The air plenum 340 can accumulate the hot air from the heater
core 300 at an
elevated pressure to force and direct the hot air into the heating ducts 345,
which lead air back
inside the RV. In one example, the entire blower compartment 102b can be the
air plenum 340.
Return air circulating in the lower radiator chamber 113 can be preheated from
the radiator tank
200 to increase the efficiency of the system. When the blower 325 is activated
to generate
heated air, the heater core 300 can provide convective heat transfer from the
heated water
running through the tubing inside the heater core 300 to the return air drawn
in from the upper
radiator chamber and the lower radiator chamber until the desired room
temperature is reached,
at which time the RTS can send a signal to shut off or deactivate the blower
325.
From the heater core 300, the heated water flows through a one-way valve 190
before
returning back to the radiator tank 200. Thus, a heating loop can be formed
from the radiator
tank 200, the heat exchanger 250, the heater core 300, and back to the
radiator tank 200. The
one-way valve 190 can be provided downstream of the heater core 300 to prevent
water from the
water inlet 106 to enter the heater core 300 or flow through the water outlet
108 other than
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through the mixing valve 150. The one-way valve 190 can ensure only heated
water leaving the
heater core 300 can pass through the mixing valve 150.
As shown, the pump 170 is located downstream of the radiator tank 200 in the
blower
compartment 102b, but can be located in the burner compartment 102c, the
radiator compartment
102a along the heating loop, or elsewhere within the housing. In one example,
the pump 170 is
an electric activated water pump controlled by a microprocessor of a control
board 350 and
operated to circulate the water through the heating loop when the hydro-
furnace 100 is powered
on and a temperature of the water in the radiator tank is below a minimum tank
temperature to
provide hot water and/or heated air.
The pump 170 can continually circulate the water through the heat exchanger
250 until
the average temperature of the water in the radiator tank 200 reaches a
threshold temperature,
such as, for example, 160 degrees F or some different set point temperature.
Once the average
temperature of the water in the radiator tank 200 reaches the threshold
temperature, such as 160
degrees F, the pump 170 and the burner 275 can shut off. If the water in the
radiator tank 200
falls below a minimum tank water temperature, such as 140 degrees F, the pump
170 and the
burner 275 can switch on until the average temperature of the water in the
radiator tank 200
returns back to the threshold temperature, such as 160 degrees F. Thus, the
water in the radiator
tank 200 can be maintained between 140-160 degrees F.
As hot water is being dispensed through the hot water outlet 108. water from
the water
supply can enter the radiator tank to replace the dispensed hot water. Because
the newly
introduced water is typically lower in temperature than the temperature of the
water in the
radiator tank 200, the new combined temperature drops from the previous tank
temperature.
When the temperature of the water in the radiator tank falls below the minimum
tank
temperature, the pump 170 and the burner 275 are activated to generate heat
and produce
additional heated water until the minimum tank temperature is reached. The
hydro-furnace 100
is capable of producing hot water as hot water is continually used. Thus, the
hydro-furnace 100
can also function as a tankless water heater.
Turning now to FIGs. 3-6, the hydro-furnace 100 is shown without the housing
panels to
more clearly depict the part or components mounted inside the housing. More
clearly shown are
the water supply inlet 106 and the water outlet 108, which are in line with
each other and
connected with the tubing 114. As shown and further discussed below, the water
supply inlet
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106 and the hot water outlet 108 can be located externally of the housing 102,
such as externally
of the left side of the hydro-furnace 100 of the housing 102 for quick access
by a user. The gas
inlet 104 can be located on the right side of the hydro-furnace 100.
Optionally, tubing and mechanical and electrical components can be located, at
least in
part, outside of the panels of the housing 102 to facilitate assembly and
maintenance, among
other things. Incoming water or water to be heated from a water supply or
source can enter the
hydro-furnace 100 through the water inlet 106 extending out of the housing
102. In one
example, the water inlet 106 can be a threaded male connector for engaging a
threaded female
connector from a water supply. In another example, the water inlet 106 can be
a smooth pipe
with or without a hose barbed end to receive a hose or tubing connected to the
water supply. A
clamp can further secure the hose or tubing to the water inlet 106.
As shown, the water inlet 106 can have a standard fitting to readily accept a
water feed
line or inlet water source. For example, the water supply inlet 106 can
comprise an industry
standard connection fitting for attaching to a water supply or cold water
supply line. The hot
.. water outlet 108 similarly can comprise an industry standard connection
fitting for attaching to
plumbing lines that then carry heated water to user stations, such as to sinks
and baths/showers
located elsewhere in the RV on which the hydro-furnace 100 for the RV is
mounted. In one
example, the water supply inlet 106 and hot water outlet 108 can include a
quick connect
coupling or a threaded collar.
Unlike a water heater or furnace installed in a permanent structure, such as
in a home
which has a generally stable water supply temperature and pressure, an RV with
a hydro-furnace
100 moves from water supply source to water supply source when on the road
travelling from
point A to point B, etc. The hydro-furnace 100 for the RV should be able to
produce water at the
desired temperature from widely varying water supply temperatures while still
maintaining a
relatively small size or profile to fit within the portable environment of the
RV.
The water inlet 106 inside the housing 102 can transition into a multi-flow
fitting 130,
such as a four way pipe fitting or a four way tee, used to combine and/or
divide fluid flow. In an
example, the multi-flow fitting 130 can be four individual fittings oriented
90 degrees apart to for
a four way tee. However, multiple back to back tees can be used to split the
flow into multiple
streams. In one example, the water inlet 106 is coupled to a first fitting of
the four way tee 130,
a hot water return line 132 from the heater core 300 is coupled to a second
fitting of the four way
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tee 130, the radiator tank 200 is coupled to a third fitting of the four way
tee 130, and a mixing
valve 150 is coupled to a fourth fitting of the four way tee 130 via a cold
water output line 134.
Thus, the four way tee 130 allows water from the water inlet 106 to flow into
the radiator tank
200 and to the mixing valve 150, which is further discussed below.
The radiator tank 200 is located in the radiator compartment 102a and can
store water
received from the water inlet 106 and the hot water return line 132. The
temperature of the water
inside the radiator tank 200 can be monitored by one or more temperature
sensors and
maintained and controlled at an optimum tank temperature, such as between 140-
160 degrees F,
using control circuitries, a controller, or a control board, as further
discussed below with
reference to FIGs. 8 and 9.
As the temperature of the water inside the radiator tank 200 increases, so
does the
temperature of the radiation tank 200. A tank emergency cutoff thermostat
(TECO) 351 for
preventing the temperature of the water inside the radiator tank 200 from
increasing past a
maximum tank water temperature, can be positioned on a surface of the radiator
tank 250. In
one example, the maximum tank water temperature is 170 degrees F. In another
example the
maximum tank water temperature can be other than 170 degrees F. In one
embodiment, the
TECO 351 can be a disc thermostat that prevents the burner 275 from firing
when the
temperature of the water in the radiator tank 200 exceeds the maximum tank
water temperature.
As previously mentioned, return air can be pulled by a blower 325 located in
the adjacent
blower compartment 102b, from both the upper radiator chamber, which draws the
return air
from outside the hydro-furnace 100 through the upper return air vent 107, and
the lower radiator
chamber, which draws the return air from outside the hydro-furnace 100 through
the lower return
air vent 109. In one example, the radiator tank 200 can be located in the
lower radiator chamber
of the radiation compartment 102a. Thus, the return air in the lower radiator
chamber can be
preheated by convective heat transfer from the radiator tank 200 as it travels
from the radiator
compartment 102a to the blower compartment 102b.
The radiator tank 200 can comprise a radiator tank body 205 having a storage
space
configured to store the heated water, an inlet radiator cover 215 at an inlet
end of the radiator
tank body 205, and an outlet radiator cover 220 at an outlet end of the
radiator tank body 205. A
plurality of fins 210 extending from the exterior of the radiator tank body
205 may also be
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provided to increase convection from between the radiator tank 200 and the
return air in the
radiator compartment 102a.
The inlet radiator cover 215 can be similar or identical to the outlet
radiator cover 220.
The inlet and outlet radiator covers 215, 220 can be circular and sized to fit
at opposite ends of
the radiator tank body 205 to cover the interior space of the radiator tank
body 205. A watertight
seal such as an 0-ring or gasket can be provided between the radiator covers
215, 220 and the
radiator tank body 205. An inlet opening 217 through the inlet radiator cover
215 can allow
water from the inlet and/or the hot water return line 32 from the heater core
300 to flow inside
the radiator tank body 205. An outlet opening 222 through the outlet radiator
cover 220 can
allow water from inside the radiator tank body 205 to flow to the heat
exchanger 250.
A size or diameter of the inlet and outlet openings 217, 222 can be smaller
than a size or
diameter of the interior cavity or bore of the radiator tank body 205 so that
a volume of water can
be maintained inside the radiator tank body 205. In one example, the radiator
tank body 205 can
store 2-4 gallons of water. In other examples, the tank body can store a
different volume of
water. The location of the inlet opening 217 and the outlet opening 222 can
affect water flow
and temperature mixing inside the radiator tank body 205. In one example, the
inlet opening 217
can be adjacent an outer perimeter of the inlet radiator cover 215, and the
outlet opening 222 can
be adjacent an outer perimeter of the outlet radiator cover 220, with the
inlet opening 217 and
outlet opening 222 diametrically opposed at opposite ends of the heat
exchanger 250 to provide a
longer path through the radiator tank body 205. This can ensure better mixing
than a shorter
direct path between the inlet and outlet openings 217, 222.
Referring to FIG. 4, water from the radiator tank 200 can exit out the outlet
222 and flow
to the heat exchanger via a radiator tank output line 136. A pump 170 can be
positioned inline
and downstream of the radiator tank 200 along the radiator tank output line
136. In one example,
the pump 170 can be located between the heat exchanger 250 and the radiator
tank 200 along the
radiator tank output line 136 inside the blower compartment 102b. The pump 170
can be a
standard electric driven water pump. The pump 170 can be controlled directly
or indirectly by
control circuitry as previously discussed and further below with reference to
FIGs. 8 and 9. As
described above, water is pumped out from the radiator tank 200 to the heat
exchanger 250
where it is heated and passes through the heater core 300 before being
dispensed through the
mixing valve 150 to the water outlet 108 and to a faucet or shower and/or
return back into the
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radiator tank 200, thus forming the heating loop. The pump 170 can actively
circulate the water
until the radiator tank 200 reaches some set point, such as 160 degrees F, at
which time the
burner 275 can switch off. The pump 170 can be shut off simultaneously with
the burner 275 or
a short time thereafter. In other examples, the pump 170 can be positioned
anywhere along the
heating loop as described above.
A low temperature sensor (LTS) 354 (FIG. 8) or alternatively an input
temperature probe
(Tin) 355 (FIG. 9) for measuring the temperature of the water can be connected
inline and
downstream of the radiator tank 200. The LTS 354 can be a disc thermostat that
provides a heat
request signal to the burner 275 when the water temperature in the radiator
tank 200 drops below
a minimum tank water temperature. The Tin 355 can be a thermistor probe that
monitors the
water temperature. In one example, the minimum tank water temperature is 140
degrees F. In
the illustrated embodiments, the LTS 354 or Tin 355 can be located downstream
of the radiator
tank 200 before reaching the pump 170 or downstream of the pump 170 at or
before the heat
exchanger 250. Other sensors can be used or a combination of sensors can be
used to read and
provide input to the controller to control the burner 275.
The radiator tank output line 136 can be coupled to a heat exchanger tubing
252 as
illustrated in FIGs. 6A and 6B. The heat exchanger tubing 252 can wrap around
the exterior of
the heat exchanger 250, which can be a conductive body having a skirt or a
plenum 251. The
plenum 251 and the heat exchanger tubing 252 can be made of a conductive
material, such as
aluminum, copper, copper alloy, brass, brass alloys, or other conductive
metals. In other
embodiments, the plenum 251 and the heat exchanger tubing 252 may be made from
other
corrosive resistant materials, or plated or coated with corrosive resistant
material, that are able to
withstand the direct or indirect heat of the burner 275.
The heat exchanger tubing 252 can wrap around the plenum 251 so that water
flows from
a bottom end 253 of the plenum 251, elevation-wise, towards a top end 255 of
the plenum 251
inside the tubing, and by conduction is heated by the plenum 251 which then
heats the water
running through the heat exchanger tubing 252, similar to a preheat. Because
both the plenum
251 and the heat exchanger tubing 252 can be made from a conductive material,
heat energy is
transferred by conduction from the plenum 251 to the heat exchanger tubing 252
and from the
heat exchanger tubing 252 to the water running therein. As a result, the water
running around
the plenum 251 inside the tubing is pre-heated before entering the heat
exchanger 250. The
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water in the heat exchanger tubing 252 then enters the heat exchanger 250 so
as to be heated by
the heated gas from the burner 275, as further discussed below.
The plenum 251 can have an opening with a passage extending from the bottom
end 253
to the top end 255. Within the plenum 251, a plurality of spaced apart
internal fins (not shown)
can be located in the opening between the bottom end 253 and the top end 255
to provide
additional heat transfer paths to the heat exchanger 250. In one example, the
internal fins are
located near the top end 255 to provide space for the burner 275. The internal
fins can be closely
spaced or loosely spaced inside the plenum 251 to form baffles or channels for
the flow of heated
air from the bottom end 253 of the heat exchanger 250 and then rising through
the internal fins
and out the top of the heat exchanger 250, elevation-wise. The number of
internal fins and the
surface area of each of the internal fins can depend on the desired heat
exchange rate by
convection, conduction, and radiation exchanging with the interior run line of
the heat exchanger
tubing 252.
The heat exchanger tubing 252 passes through the internal fins and wherein U-
shaped
returns are provided on outer surfaces on opposite sides of the plenum 251 to
connect the parallel
tubing sections in a serpentine fashion within the interior space of the
plenum 251. Thus, the
heating pipe 252 can form continuous passes through the opposite sides of the
plenum 251 and
the internal fins to maximize the heat transfer from the internal fins to the
heat exchanger tubing
252 to heat the water flowing therein. The number of fins and the total tubing
length passing
inside the plenum 251 can be selected to control the residual time of water
travelling through the
plenum 251 and the amount of heat transferring directly from the burner 275 to
the plenum 251
and from the burner 275 to the fins and then to the heat exchanger tubing 275.
An exhaust system 257 comprising an exhaust conduit can be provided to collect
exhaust
fumes rising from the burner 275 and direct the exhaust fumes away from and
outside the burner
compartment 102c through the burner outlet vent 105. As shown, the exhaust
system 257 is
positioned at the top of the plenum 251 and coupled directly to the top end
255 of the plenum
251. The exhaust system can extend horizontally towards the burner outlet vent
105. The
exhaust system 257 can have a larger opening at the output end to provide an
open flow path to
the burner outlet vent 105 for the combustion byproducts.
The exhaust system 257 can be sealed to ensure the combustion byproducts flow
directly
out the burner outlet vent 105. An exhaust fan powered by an exhaust fan motor
may also be
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provided to assist directing the exhaust fumes through the burner outlet vent
105. The exhaust
fan may be connected to a microprocessor of a controller such as the DSI board
explained further
below. The DSI board can operate the exhaust fan motor to turn the exhaust fan
on and off based
on signals sent to the microprocessor from one or more sensors. For example,
whenever the
burner is activated to burn fuel, the exhaust fan is also activated to exhaust
gas. The exhaust fan
can also be activated when the burner is not in service to move air through
the system for cooling
or venting purposes. A vent duct may also extend away from the housing 102
surrounding the
burner outlet vent 105 to direct the exhaust fumes away from the hydro-furnace
100 and the RV.
The exhaust fan may be located inside the vent duct instead of inside the
housing 102.
Additional ducting may be provided to direct the exhaust gas through the
burner outlet
vent 105 and out, such as out an opening to an exterior of the mobile or
recreational vehicle. In
some examples, an induced draft fan, a force draft fan, or both can be
incorporated to move gas
through the hydro-furnace 100.
In some examples, inlet and outlet headers are provided within the heat
exchanger 250.
For example, the heat exchanger tubing 252 can direct inlet water to the inlet
header that then
separates the single inlet feed line into multiple parallel run lines inside
the heat exchanger 250.
The multiple run lines are then routed to an outlet header that then
consolidates the various run
lines into a single outlet line, which then exits the heat exchanger 250 and
flow into the discharge
or outlet line 124.
In the embodiment shown, the heat exchanger tubing 252 wraps around the plenum
251
of the heat exchanger 250 three times in the form of loops, such as continuous
loops or in
sections that are joined. In other embodiments, the heat exchanger tubing 252
may have fewer
than three loops wrapping around the plenum 251 or more than three loops
wrapping around the
plenum 251. The length of the heat exchanger tubing 252 and the number of
loops formed or
wrapped around the heat exchanger 250 can depend on the residual time desired
to route the
water through the heater, the number of tie-ins needed to connect the various
component, and the
desired preheat, among others.
The burner 275 can be positioned immediately adjacent the heat exchanger 250
and
provide the heating source to heat the exchanger 250. In an example, the
burner 275 is
positioned below the heat exchanger 250, elevation-wise, so that hot air and
combust gas
generated from the burner rise through the heat exchanger 250. In an example,
the burner 250
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can have a wide tip having multiple gas discharge holes to provide a large
distributed flame
profile. The tip can comprise a plurality of plate-like structures positioned
side-by-side with
each plate having a plurality of discharge holes formed on an edge thereof for
gas flow. The tip
can alternatively have a circular ring shape, a rectangular shape, an
elliptical shape, a square
shape, or other shaped tips provided the number of discharge holes are
selected to produce
sufficient BTU for a given gas type and gas pressure.
The burner 275 can comprise a burner pad 276 extending at least partially into
the
plenum 251 through the opening at the bottom end 253 to provide heat inside
the plenum 251.
The amount of heat provided to the plenum 251 to heat the water circulating in
the heat
exchanger tubing 252 depends on the power output of the burner 275. The burner
275 generates
heat by the combustion of gas. The fuel or gas is supplied to the burner 275
through the gas inlet
104 extending outside of the housing 102. The gas is directed from the gas
inlet 104 to a fuel or
gas control valve 278, which is configured to control the flow of gas into a
burner pad 276
located beneath or at least extending partially inside the boiler heat
exchanger 250 through the
bottom end 253 of the boiler heat exchanger 250. In one embodiment, the gas
control valve 278
can open and operate in one of two stages: a high stage (HI) and a low stage
(LO), as discussed
further below. When not in use, the gas control valve 278 can cut off the
supply of gas or shut
off. When the gas control valve 278 is on HI, the output of gas is at a high
BTU rating, and
when the gas control valve 278 is on LO, the output of gas is at a lower BTU
rating.
Alternatively, the can control valve 278 can be a variable gas control valve.
The multiple gas discharge holes of the burner pad 276 can be a series of
nozzles (not
shown) for the gas to pass therethrough. An ignition control box 280 can
comprise a direct spark
ignition (DS1) board 285 having a microprocessor and ignition control
electronics including a
spark igniter, which can be controlled to ignite the gas leaving the nozzles
to combust the gas
and produce heat. The ignition control box 280 and the gas control valve 278
can be controlled
directly or indirectly by control circuitry as discussed below with reference
to FIGs. 8 and 9.
Referring now to FIG. 6A, the heat exchanger tubing 252 can exit the heat
exchanger 250
and connect to an input port 302 of the heater core 300 via a connector tubing
138. In the
illustrated embodiment, the heat exchanger tubing 252 exits the heat exchanger
250 near the top
end 255 of the heat exchanger 250. A boiler heat exchanger emergency cutoff
thermostat
(BECO) 356 (FIGs. 8 and 9) can be provided to detect whether the temperature
of the water
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leaving the heat exchanger 250 exceeds an absolute maximum heated temperature
to cut power
to the burner 275. In one example, the absolute maximum heated temperature is
185 degrees F
with other maximum values contemplated, such as lower or higher than 185
degrees F. The
BECO 356 can be connected inline and downstream of the heat exchanger 250. In
one example,
the BECO 356 is a disc thermostat that turns off the burner 275, or sends
signals to the controller
to then turn off fuel to the burner, when the water temperature at the output
of the heat exchanger
250 exceeds 185 degrees F. In an example, when the max temperature is sensed,
the emergency
shut off valve is activated to block all fuel to the burner. When the burner
275 is not on, the
pump 170 can also turn of. Conversely, the pump 170 can be operational when
the burner 275 is
on.
A high temperature sensor (HTS) 357 (FIG. 8) or an output temperature probe
(Tout) 358
(FIG. 9) for monitoring the temperature of the water downstream of the heat
exchanger 250 can
be placed adjacent, downstream or upstream, to the BECO 356 to stop the burner
275 when the
water temperature at the output of the heat exchanger 250 exceeds a maximum
heated water
temperature. In one example, the maximum heated water temperature can be 175
degrees F.
Referring now to FIG. 5, the heater core 300 transfers heat from the water to
the return
air supplied by the blower 325. The heater core 300 comprises a core body 301
having a box
like shape mounted in the blower compartment 102b on a panel separating the
radiation
compartment 102a from the blower compartment 102b. The core body 301 is shown
having a
hollow rectangular shape with a rear opening 302 facing the radiator
compartment 102a and a
front opening 303 facing towards the blower 325. Flanges 304 can extend from
each side of the
rear opening 302 (FIG. 2) to attach to the central panels of the radiator
housing 110 and/or main
housing 120. The rear opening 302 can communicate to the radiator compartment
102a, and
more specifically, the upper and lower radiator chamber through the upper
rectangular cutouts
111, 121. The front opening can be coupled directly to a suction port 326 of
the blower 325.
The blower 325 circulates air from the interior space of the mobile vehicle or
RV through
the radiator tank 200 and the heater core 300 to the air plenum 340 and back
to the room through
air ducts 345. The blower 325 has a suction port 326 to draw in air and a
blower port 327 to
blow air out. Thus, the blower 325 can function as a vacuum. Alternatively,
the ports can be
reversed, or a different type of blower 325 can be used, as desired.
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A room thermostat (RTS) 360 outside the hydro-furnace 100 can be preprogrammed
or
operated by a user to generate and transmit a heat request for air heating or
space heating. The
RTS can be connected to control circuity of the hydro-furnace 100 to activate
the pump 170, the
burner 275, and the blower 325 when powered "ON". The RTS can also send
signals to the
control circuitry of the hydro-furnace 100 to stop the blower, pump, and/or
burner when an
interior set point is reached.
In one embodiment, the gas control valve 278 can be set between a high setting
(HI) and
a low setting (HI). Alternatively, the gas control valve 278 can be variable.
The gas control
valve 278 can be normally set on HI until the water in the radiator tank 200
is within the
minimum tank water temperature and the threshold temperature, such as between
140-160
degrees F, or above the threshold temperature, at which time the gas control
valve 278 can
switch to LO.
In one example, when the blower 275 is activated by the RTS 360, the power to
the
blower 325 is applied to this connection and reduces the output of gas to the
lower BTU rating.
That is, the gas control valve 278 is on LO. The burner 275 can also be
activated by the RTS
when the RTS is not powered "ON" and the water temperature in the radiator
tank 200 falls
below the minimum tank water temperature, such as, in one example, 140 degrees
F. Thus,
when water is to be heated or air is to be heated, but not both, the gas
control valve 278 can
operate on LO. When both water and space are to be heated simultaneously, the
gas control
valve 278 can be on HI. In an example, the LO setting can be about 12K to
about 18K BTU, and
the HI setting can be about 35K to about 37K BTU. A relay (R) 359 can prevent
the gas control
valve 278 from switching to LO if both the water heating and space heating are
used
simultaneously. The pump 170 can be operating continuously while the burner
275 is on.
Within the core body 301 of the heater core 300, a plurality of spaced apart
fins 305 are
provided. The fins 305 can be closely spaced or loosely spaced inside the core
body 301 to form
baffles or channels for the flow of return air from the radiator compartment
102a through the
heater core 300 generated by the suction of the blower 325. The number of fins
can depend on
the desired heat exchange rate by convection, conduction, and radiation
exchanging with the
interior run line of the heater core tubing 310. The heater core tubing 310
passes through the fins
and wherein U-shaped returns are provided on opposite exterior surfaces of the
heater core body
301 to connect the parallel tubing sections in a serpentine fashion within the
interior space of the
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heater core 300. The number of fins and the total tubing length passing inside
the heater core
300 can be selected to control the residual time of water travelling through
the heater core 300
and the amount of heat transferring directly from the heater core tubing 310
to the fins and then
to the return air. In one embodiment, the heater core tubing 310 and the fins
are made from a
highly conductive material, such as copper, brass, or their alloys.
A pneumatic resistance screen 315 can be provided inside the heater core 300
between
the fins 305 and the front opening 303 to increase the efficiency of the
heater core 300. The
pneumatic resistance screen 315 can reduce the velocity of the return air
pulled into the suction
port 326 of the blower 325 to increase the resistance and therefore heat
transfer from the heater
core tubing 310 and the fins 305 to the return air as it passes through the
fins 305 into the blower
325.
A three-way tee 131 can bifurcate the line from the heater core 300 to direct
the heated
water to the mixing valve 150 and back to the radiator tank 200 through the
one-way valve 190
and the hot water return line 132. In one example, if hot water is not being
used, such as not
exiting the water outlet 108, then the water will circulate back into the
radiator tank. If some hot
water is used, then only the remaining portion of hot water not leaving the
hydro-furnace 100
will be returned to the tank. As hot water leaves the hydro-furnace 100, water
from the water
supply can flow into the water inlet 106 to replace the heated water leaving
the hydro-furnace
100. Thus, the amount of water held in the hydro-furnace 100 can remain
relatively constant.
FIGs. 8 and 9 illustrate two different embodiments of a control system for
controlling
operation of the hydro-furnace 100. FIG. 8 illustrates an electro-mechanical
control system
based on a direct spark ignition (DSI) board 285 to provide the required
safety features. FIG. 9
illustrates an electronic control system which uses a DSI board 285 and a
separate electronic
control board that monitors the water temperature using thermistor probes
rather than thermostats
at various locations.
Referring to FIG. 8, the ignition control box 280, which can house the DSI
board 285,
can comprise a control box base 281 and a cover 282. The cover 282 can be
flush with the
surface of the housing 102 or extend partially out from the housing surface.
Alternatively, the
cover 282 can remain inside the housing 102. In one embodiment, the electro-
mechanical
control system is similar to those found in standard furnaces and water
heaters. The DSI board
285 is a microprocessor based control board that operates all functions of the
hydro-furnace 100
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and provides terminal connections for power, such as +12V, grounding, the gas
control valve
278 to open and shut off the gas to the burner 275, ignition terminal for the
spark igniter to light
the burner, a remote indicator (LGT) to provide feedback on the hydro-furnace
100 operation
and possible faults, and a safety loop to verify that the TECO 351 and BECO
356 are not open.
The LGT can provide feedback and alerts in the form of LEDs located on the
cover 282 of the
ignition control box 280, a surface of the housing, or a control panel located
away from the
housing 102. Optionally, an audible alarm may be incorporated to provide
alerts.
A DSI board 285 provided herein can be a microprocessor based control board
that can
operate all the function of the hydro-furnace 100 according to safety and
regulation standards
and provide connections and controls for a sufficiently voltage for activating
the ignition to the
burner, a ground connection, the control of the gas valve 278 to open, shut
off, and the control of
gas flowing to the burner 275, remote indicate (LED) power to provide feedback
on operation of
the hydro-furnace 100 and possible faults, and safety loop to verify that the
TECO and BECO
thermostats are not open, among others.
The power terminal of the DSI board can be connected to a DC power supply
source,
such as the battery power supply source of the RV via a power cable. The
grounding terminal
can be connected to a grounding cable to the RV to ground the circuit. The DSI
board 285 and
the microprocessor in the DSI board 285 of the hydro-furnace 100 can accept
different voltages,
such as 12 Volt DC to 24 Volt DC. Generally, 12 Volt DC can be produced by the
on-board
power system of the RV to power various auxiliary devices. The power can be
tied or linked to
the ignition system or supplied from a battery bank with fulltime power, as is
well known in the
RV industry. The battery bank that supplies fulltime power can be charged by
the vehicle's
generator or by plug-in AC power when the RV is plugged into an AC source.
In addition to the DC connector port discussed above, an I/O connector port
can be used
to set control parameters for the controller. Like the DC connector port, the
I/O connector port
can be a passage or bore through the housing 102 having a plastic ferrule or
liner that allows one
or more cables to pass therethrough for connections between the electric
system of the water
heater, such as the microprocessor, and a control panel, which can be mounted
remotely from the
hydro-furnace 100, such as near the kitchen, bathroom, or the vehicle
dashboard. Power may be
supplied to the thermostats and sensors, such as the TECO. BECO, LTS, and HTS,
through the
DSI board 285 or separately from the DC power source of the RV.
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The ignition terminal can be provided for the ignitor high voltage wires,
which supply the
necessary power to ignition control electronics including the ignition control
spark to supply the
ignition source for the burner 275.
The RTS 360 can be connected to the DC power supply source, the relay (R) 359,
the
blower 325, the thermostats and temperature sensors, and the pump 170.
Various functions of the hydro-furnace 100, such as set temperature, water
flow rate, and
air flow rate, may be controlled by the DSI board 285. The microprocessor in
the DSI board 285
can act as a gateway for receiving signals and data from the various sensors
and is programmed
to control operation of various components of the hydro-furnace 100 based on
the received
signals and data, as further discussed below. For example, based on the
temperature data
received from one of the thermostats or probes, the microprocessor can send
control signals to
the gas control valve 278 to modulate gas flow feeding the burner 250.
The controller or DSI board 285 of the hydro-furnace 100 can be connected to
an
onboard fulltime DC power supply of the RV and not dependent on the car
ignition system. By
.. connecting to the vehicle's fulltime power, the DSI board 285 is always
powered and various set
points using a control panel and various parameters and data used by the
microprocessor can be
maintained or saved. In other examples, the DSI board 285 is equipped with
auxiliary memory
that stores set points and parameters and can retain the information even when
power is
disconnected to the DSI board 285. When auxiliary memory is incorporated, the
DSI board 285
can be supplied with the vehicle's generator power.
Referring now to FIG. 9, the electronic control system is similar to the
electro-
mechanical control system of FIG. 8, except that an electronic control board
350 is used to
monitor the water temperature using thermistors instead of thermostats. In an
example, the LTS
354 and HTS 357 of the electro-mechanical control system of FIG. 8 are
respectively replaced by
the thermistor probes Tin 355 and Tout 358 of the electronic control system.
The Tin probe 355
can be placed at the input of the heat exchanger 250 and the thermistor probe
Tout 358 can be
placed at the output of the heat exchanger 250 downstream of the BECO. The
electronic control
system can further include a thermistor probe Ti 361 located at the top of the
radiator tank 200
and a thermistor probe T2 362 located at the bottom of the radiator tank 200
to determine the
state of mixing of the water and, indirectly, the water heating function. In
another example, the
Ti probe 361 can be located at the upstream end of the radiator tank 200 and
the T2 probe 362
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can be located at the downstream end of the radiator tank 200. The electronic
control board 350
can directly activate the pump 170 and the blower 275 based on precise values
measured by
thermistor probes Ti 361, T2 362, Tin 355, Tout 356, which can be directly
connected to the
electronic control board 350.
The DSI board 285 in the electronic control system is also similar to the
electromechanical control system of FIG. 8, except that the power terminal is
now connected to
the electronic control board 350 instead of the thermostats and temperature
sensors. The RTS
360 can also be connected directly to the electronic control board 350. Thus,
operations in the
electronic control system of FIG. 9 can be handled by the electronic control
board 350. More
precisely, a microprocessor in the electronic control board 350 can receive
and send signals to
power and control the components in the hydro-furnace.
Referring to FIG. 10, another embodiment of a hydro-furnace 100 is shown. The
hydro-
furnace 100 can be similar to the hydro-furnace 100 of FIG. 1 with a few
exceptions. In the
present embodiment, the heated water can be stored in a coil reservoir 240
instead of a radiator
tank 200. The coil reservoir 240 can be a tubular structure that can extend
between opposite
sides of the radiator compartment 200a in a serpentine fashion with U-shaped
ends connecting
parallel tubing sections extending in opposite directions within the interior
space of the plenum
251. As shown, the coil reservoir 240 forms a plurality of loops confined
within the lower
radiator chamber of the radiator compartment 200a. Each of the plurality of
loops can be spaced
apart from each other to allow return air to be drawn outside the hydro-
furnace 100 from the
lower return air vent 109 through each of the loops or tubing sections. Return
air in the Heat can
be transferred from the coil reservoir 240 into the return air inside the
radiator compartment 102a
or lower radiator chamber before being drawn through the heater core 200 into
the blower 325.
Thus, like the radiator tank 200, the coil reservoir 200 can pre-heat the
return air to improve
.. heating efficiency of the hydro-furnace 100.
In still other examples, additional probes and/or sensors can be connected in-
line with the
various tubing and lines of the hydro-furnace 100 in either system for sensing
and controlling or
regulating other flow functions in either the electro-mechanical system or the
electronic control
system. Other sensors such as pressure and flow sensors may be added for more
advanced
functions to improve performance, such as user selection of performance
parameters,
troubleshoot capabilities to identify various system failures, warnings to the
user of potential
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failures, and remote control of all features from a panel or handheld unit or
via internet access.
The various connections can be threaded, welded, by mating flanges, or
combinations thereof. In
some examples, a threaded bore is provided on a side of a fitting, such as a
threaded socket or a
threaded thermowell, for receiving a probe, which can include a thermostat, a
flow sensor, or
other sensing devices. Optionally, welding may be used to connect the various
components and
tubing sections.
As available space can be limited in RVs, the present disclosure provides for
modularization of the components of the hydro-furnace system 100. For example,
the system
100 can be generally separated into segmented sub-systems that can be stored
or mounted in
.. spaced apart configurations. In an example, the hydro-furnace system 100
can be separated into
a water heater module 1110, a tank module 1120, and a hydro-furnace module
1130. The
modules can be located separately from one another, such as spaced from one
another in
different segmented structures, throughout the RV, with necessary connections
between them. In
this way, the components of the hydro-furnace 100 system can be installed in
small spaces in the
RV that already exist and are relatively easier to access without the need for
designing a
sufficiently large space for a single unit system. Additionally, the
modularization can allow for
modular sizing of components to fit the needs of the specific RV. For example,
a larger RV may
require a large storage tank 200 or blower 325. In some examples, the hydro-
furnace system 100
can be separated into two or more sub-systems that can be mounted in spaced
apart
configurations.
The separation of the components can provide a benefit for better isolation of
the water
heater unit and the exhaust system, which can produce emissions byproducts
from the burner 275
that can be harmful if introduced into the interior of the RV. The other
benefit, as previously
described, is the flexibility of storing sub-components or sub-systems in
multiple smaller spaces
throughout the RV instead of a single large space.
FIGs. 11-15 show a schematic flow diagram and components of a modularized
hydro-
furnace system as might be installed on an RV or other mobile vehicles, such
as a boat.
FIG. 11 illustrates a schematic layout for a modularized hydro-furnace system
100 using
an electronic control system. FIGs. 12 and 13 illustrate exemplary
implementations of the
different sub-systems. The hydro-furnace system 100 can have a water heater
module 1110 that
contains a water heater or water boiler 275. The water heater can be
controlled by an electronic
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control board 350 acting in response to a thermostat 360 that monitors the
water temperature
using thermistor probes 1152. The electronic control system can use a DSI
board as described in
FIGs. 8 and 9 to control the water heater.
The room thermostat 360 can generate a heat request for space heating as
desired by a
user. The electronic control board 350 can receive the heat request from the
room thermostat
360 and control the components of the hydro-furnace system 100 as necessary to
provide the
requested heat.
The electronic control board 350, though the DSI board, can control a burner
275 in the
water heater module 1110 as understood from at least FIGs. 4, 8, 9, 12, and
13. The water heater
module 1110 can receive water from a cold water source 106 or from the storage
tank 200. In an
initial state, the system is primed with water from the cold water source 106.
The water input into the water heater module 1110 can be heated and then
either supplied
as warm water through a warm water line 108 to the user or as heated water
through the hydro-
furnace water circuit 136 to provide heat to the RV.
From the water heater module 1110, the heated water can flow through the hydro-
furnace
water circuit 136 to the hydro-furnace module 1130. There, the heated water
can flow through a
heat exchanger 300. A blower 325 can move air across the heat exchanger to
heat the air from
heat transferred from the heated water. The blower 325 and the heat exchanger
300 are
described further with reference to FIG. 15. The blower 325 can be controlled
by the electronic
control board 350. The heated air can then be distributed to the interior of
the RV through the air
vents 107 of the hydro-furnace module 1130. To improve the efficiency of the
hydro-furnace
module 1130, there can be provided a pneumatic resistance screen 315 in front
of the heat
exchanger 300. This can increase the efficiency of the heat exchanger 300 by
increasing the
residual contact time with the heat exchanger, such as by reducing the
velocity of the air being
moved by the blower 325.
After circulating through the heat exchanger 300 of the hydro-furnace module
1130, the
heated water flows to the tank module 1120. There, the heated water flows
through a one-way
valve 190 before flowing into the tank 200 through a manifold 1128. Water from
the tank 200
can then be recirculated to the water heater module 1110 through a downstream
one-way valve
1124 by way of a pump 170 and a solenoid valve 1126. The pump 170 can actively
circulate the
water through the water heater module 1110 until the temperature of the
storage tank 200 reaches
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a desired temperature. The temperature can be checked by way of a temperature
probe 1152
downstream of the storage tank 200. The electronic control board 350 can
control the pump 170,
solenoid valve 1126, and blower 325 based upon the readings from the
thermostat 360 and the
temperature probe 1152.
The use of the one-way valves 190, 1124 prevent mixing of water in the
different phases
of the heating loop. Upon the water of the storage tank 200 reaching the
desired temperature, the
electronic control board 350 can shut off the burner 275 of the water heater
module 1110.
As scalding is based on both temperature and duration of contact, the present
disclosure
provides for a mechanism to prevent the risk of scalding to the user. The
water heater module
1110 can be designed to provide a predetermined amount of maximum heating to
the water. In
this way, the maximum temperature of water heated from the cold water source
106 can be
limited to prevent scalding of a user when delivered for use through the water
outlet 108.
To increase the heat of the water of the heating loop of the hydro-furnace
system 100, the
water from the heating loop can be continually cycled to water heater module
1110 and heated.
In this way, the water can be heated to a higher temperature than that of the
water delivered to
the user.
Additionally, the heated water of the hydro-furnace system can be cut-off to
the user by
means of both the pump 170 and the solenoid valve 1126. Use of the solenoid
valve allows for
quick shut off of the flow of water from the stored water from flowing to the
water heater. In
this way, stored water that is hot is prevented from flowing into the water
heater and being
output to the customer. As a result of the shut off of flow from the stored
water, the temperature
of the water input into the water heater is limited by the inflow of cold
water. The resulting
heating of the water by the water heater is thereby limited in terms of the
temperature of the
water that can output to the user through the water outlet 108.
Furthermore an emergency cutoff (ECO) can be applied to the water outlet 108
for
preventing the temperature of the water for a user from being improperly high
even in the case of
a malfunction.
In addition to the singular hydro-furnace module 1130, there can be additional
hydro-
furnace modules 1130 installed in the RV to provide zone specific heating as
desired.
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Embodiments of the water heater utilize a gas burner. However, it can also be
envisioned
that an electric water heater can also be used, which uses resistance heating
coils or ceramic
heating coils.
Additionally, as shown in FIGs. 8 and 9, the hydro-furnace system 100 can use
alternative control systems, such as electro-mechanical.
FIGs. 12 and 13 show side and perspective views of the water heater module
1110, the
tank module 1120, and the hydro-furnace module 1130.
The water heater module 1110 incorporates a burner 275 configured to heat
water. The
water heater module 1110 has a water input 1202 for receiving cold water 106
or circulating
water from the hydro-furnace heating loop. The water input 1202 may include a
manual water
shut off valve. The water input 1202 may be on a first side of the housing
1112.
A fuel or gas inlet 104 for introducing fuel to the burner 275 in the water
heater module
1110 is shown extending out from the first side of the housing 1112. A fuel or
gas line can be
connected to the gas inlet 104 to supply fuel, such as propane, to the burner
275. As shown, the
gas inlet 104 is a male connector, however, the gas inlet 104 may be a female
connector
extending into the housing 1112, in which case a gas line having a male
connector tip can engage
the female connector to supply fuel to the burner 275. Pressure fittings may
also be used to
connect the various lines and components of the hydr0-furance system.
The water input can be coupled to a heat exchanger tubing 252 as further
illustrated. The
heat exchanger tubing 252 can wrap around the exterior of a heat exchanger
250, which can be a
conductive body having a skirt or a plenum 251. The plenum 251 and the heat
exchanger tubing
252 can be made of a conductive material, such as aluminum, copper, copper
alloy, brass, alloys,
or other metals.
The plenum 251 and the heat exchanger tubing 252 can be made from other
corrosive
resistant materials that are able to withstand the direct or indirect heat of
the burner 275, or be
plated or coated with a corrosive resistant material. The heat exchanger
tubing 252 can wrap
around the plenum 251 from a bottom end 253 of the plenum 251 towards a top
end 255 of the
plenum 251, elevation-wise, and by conduction is heated by the plenum 251
which then heats the
water running through the heat exchanger tubing 252. This can be understood as
being similar to
a preheat. Because both the plenum 251 and the heat exchanger tubing 252 can
be made from a
conductive material, heat energy is transferred by conduction from the plenum
251 to the heat
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exchanger tubing 252 and from the heat exchanger tubing 252 to the water
running therein. As a
result, the water running around the heat exchanger 250 is pre-heated before
entering the heat
exchanger 250. The heat exchanger tubing 252 then enters the heat exchanger
250 so as to be
heated by the heated gas from the burner 275, as further discussed below.
The plenum 251 can have an opening extending from the bottom end 253 to the
top end
255. Within the plenum 251 of the heat exchanger 250, a plurality of spaced
apart internal fins
can be located in the opening between the bottom end 253 and the top end 255
to provide
additional heat transfer paths. In one example, the internal fins are located
near the top end 255
to provide space for the burner 275. The internal fins can be closely spaced
or loosely spaced
inside the plenum 251 to form baffles or channels for the flow of heated air
from the bottom end
253 of the heat exchanger 250 and then rising through the internal fins and
out the top of the heat
exchanger 250. elevation-wise.
The number of internal fins and the surface area of each of the internal fins
can depend
on the desired heat exchange rate by convection, conduction, and radiation
exchanging with the
interior run line of the heat exchanger tubing 252. The heat exchanger tubing
252 passes through
the internal fins and wherein U-shaped returns are provided on outer surfaces
on opposite sides
of the plenum 251 to connect the parallel tubing sections in a serpentine
fashion within the
interior space of the plenum 251. Thus, the heating pipe 252 can form
continuous passes through
the opposite sides of the plenum 251 and the internal fins to maximize the
heat transfer from the
internal fins to the heat exchanger tubing 252 to heat the water flowing
therein. The number of
fins and the total tubing length passing inside the plenum 251 can be selected
to control the
residual time of water travelling through the plenum 251 and the amount of
heat transferring
directly from the burner 275 to the plenum 251 and from the burner 275 to the
fins and then to
the heat exchanger tubing 275.
The water heated through the heat exchanger tubing 252 can then output through
water
output 1204 for delivery to the user or the hydro-furnace heating loop.
An electrical connector 1206 can be provided on the first side of the house
1112 also for
connection of the electronics housed in the water heater module. The
electrical connector 1206
may be a quick disconnect type. The electrical connector may be a plurality of
connectors for
different power and signal connections.
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An exhaust system 257 comprising an exhaust conduit or duct can be provided to
collect
exhaust fumes rising from the burner 275 and direct the exhaust fumes and away
from and
outside the water heater module 1110 through the burner outlet vent 105. As
shown, the exhaust
system 257 is positioned at the top of the plenum 251 and coupled directly to
the top end 255 of
the plenum 251. The exhaust system can extend horizontally towards the burner
outlet vent 105.
The exhaust system 257 can have a larger opening at the output end to provide
an open flow path
to the burner outlet vent 105 for the combustion byproducts.
The exhaust system 257 can be sealed to ensure the combustion byproducts flow
directly
out the burner outlet vent 105. An exhaust fan 1208 powered by an exhaust fan
motor 1209 may
also be provided to assist directing the exhaust fumes through the burner
outlet vent 105. The
exhaust fan 1208 may be connected to a microprocessor of a controller such as
the DSI board
explained. The DSI board can operate the exhaust fan motor to turn the exhaust
fan on and off
based on signals sent to the microprocessor from one or more sensors.
Additional ducting may be provided to direct the exhaust gas through the
burner outlet
vent 105 and out, such as out an opening to an exterior of the mobile or
recreational vehicle. In
some examples, an induced draft fan, a force draft fan, or both can be
incorporated to move gas
through the hydro-furnace 100.
As further shown in FIG. 14, embodiments of the tank module 1120 of FIGs. 12
and 13
can have a water storage tank 200, an upstream one way valve 190, a downstream
one way valve
1124, a pump 170, and a solenoid valve 1126. The tank module 1120 can contain
only some of
the components of the storage tank 200, the upstream one way valve 190, the
downstream one
way valve 1124, the pump 170, and the solenoid valve 1126. It is possible to
place the upstream
one way valve 190, the downstream one way valve 1124, the pump 170, and the
solenoid valve
1126 in locations along the system between the water heater module 1110, the
tank module
1120, and the hydro-furnace module 1130.
The storage tank 200 can store hot water for the hydro-furnace water circuit.
The storage
tank 200 can be an expansion tank and contain a resilient bladder certified
for the operating
temperature and pressure. The expansion tank can protect the RV water system
from excessive
pressure. The tank can be partially filled with air, the compressibility of
which absorbs excess
water pressure and/or water volume.
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The storage tank 200 may be cylindrical in shape. The storage tank 200 may be
oriented
in an upright position, with an opening 1422 at one of the end surfaces 1420a
of the cylindrical
shape, the end surface considered the downward oriented face when installed in
an RV.
The storage tank 200 can have an alternative shape, such as rectangular,
trapezoidal, or
spherical. Also, the storage tank 200 can be oriented in different directions,
such as having the
cylindrical shape be oriented on its side 1420b.
The opening of the storage tank 200 is coupled to a manifold 1128. The
manifold 1128
can include an input side 1128a connected to a tube 1129. The tube 1129 can
convey the water
from the input side 1128a to an upper portion of the storage tank 200. The
manifold 1128 can
allow for water to exit the storage tank at the bottom of the storage tank at
the opening 1422. In
this way, the tank can have heated water conveyed to the top portion while
relatively cooler,
denser water at the bottom of the storage tank 200 can be drawn.
The manifold 1128 can include a chamber area 1128c for the output side 1128b.
The
chamber area 1128c can connect to the downstream section of the piping of the
system.
The manifold 1128 can be coupled to the storage tank 200 by way of
corresponding
threading. The coupling can also be achieved by way of corresponding lugs and
grooves on the
components. The coupling can also be achieved by way of a slip fit, and can
also utilize a
clamping ring over the slip fit.
Also, the illustrated manifold of FIG. 14 shows the manifold 1128 on the
bottom surface
of the storage tank 200. However, the manifold 1128 could be attached to side
surfaces of the
storage tank 200 instead of the bottom surface. The manifold 1128 can be
attached to a lower
portion of a side surface 1420b near the bottom portion of the storage tank
200.
As shown in FIG. 14, the manifold 1128 can be a single connection point for
both the
input side 1128a and outside side 1128b. Additionally, the manifold 1128 can
also be achieved
with two connection points. The input side 1128a can be separated from the
output side 1128b.
Instead of a single connection point, the input side 1128a can be attached to
a second opening of
the storage tank 200. In such a case, the opening for the input side 1128a can
be provided where
convenient. The input side 1128a in such a case can utilize a tube 1129 as
necessary to convey
water to the upper portion of the storage tank 200.
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Alternatively, the opening may be provided at an upper portion of the storage
tank 200,
such that a tube is not necessary. Combinations of such a split connection
could have the input
side 1128a and the output side 1128b located on different surfaces of the
storage tank 200.
The connections to the storage tank 200 can be arranged as necessary to fit
the
installation layout of the RV. For example, FIG. 14 illustrates an
installation where the routing
1424 of pipe connecting the components results in a U-shape underneath the
storage tank to
minimize a footprint of the components for compactness. In this case, the
upstream one way
valve 190 can be in line with the manifold 1128. The routing can then go
through a 90 degree
bend to the downstream one-way valve 1124. After the downstream one-way valve
1124, the
routing can then go through another 90 degree bend to the pump 170 and the
solenoid valve
1126. Alterative bend configurations may be used as necessary to provide the
convenient
routing and attachment to the tank module 1120 when installed in the RV.
The upstream one way valve 190, by only allowing flow in a direction from the
hydro-
furnace module 1130 to the tank module 1120, prevents the potential mixing of
water stored in
the tank back to the water used for heating with the hydro-furnace module
1130.
Downstream of the manifold 1128. there is the downstream one way valve 1124
coupled
in line with the pump 170, and the solenoid valve 1126. The downstream one way
valve 1124
can prevent flow of water back into the storage tank 200 and mixing from
downstream. The
pump 170 can be powered to pump water from the storage tank 200 back to the
water heater
module 1110.
To minimize the risk of hot water being released, the solenoid valve 1126 can
be used to
control the flow of water from tank module back to the water heater module
1110. The solenoid
valve 1126 can be used to provide a quick shut off mechanism to prevent flow
of hot water
stored in the storage tank 200. For safety, the solenoid valve 1126 can be of
a type that is closed,
or prevents flow, in an unpowered state, or off state. In this way, if there
is a power loss to the
solenoid valve 1126, the hydro-furnace water circuit is cut-off from providing
hot water back to
the water heater module 1110.
The tank module 1120 can have a housing 1122 to house the components of the
tank
module 1120. The housing may house just the tank 200. The housing may house
some or all of
the storage tank 200, the upstream one way valve 190, the downstream one way
valve 1124, the
pump 170, and the solenoid valve 1126. The housing 1122 can be shaped to
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correspond to the storage tank 200. The housing 1122 can be shaped to
correspond to a space in
the RV or mobile vehicle. The components of the tank module 1120 can be
retained inside the
housing 1122 by being sized to fit or by retention methods such as mounting
brackets. It is not
necessary that each and every component be retained, but only that sufficient
constraining is
provided to minimize excess force from acting on the components. The use of a
housing 1122
can allow for fitment inside the RV while using off-the-shelf components,
which may be sized or
shaped differently. For example, the expansion tank can be an off-the-shelf
item that can be
easily procured for different installation types. In this way, the mere change
in dimensions for
the house 1122 is much simpler and cheaper than attempting to custom design
storage tanks 200
for different installations.
Further to FIGs. 12 and 13, FIG. 15 shows a hydro-furnace module 1130
configured to
provide heated air to the RV. The hydro-furnace module 1130 can include a
blower 325, a heat
exchanger 300, and a pneumatic resistance screen 315. Other components or
elements may be
included with the hydro-furnace module, such as fittings, brackets, sensors,
etc.
As shown in FIGs. 11 and 13, the hydro-furnace module 1130 can further include
a
housing 1132 to house the components of the hydro-furnace module 1130. The
housing can
provide air vents 107 to route the heated air into the interior of the RV.
The hydro-furnace module 1130 can receive heated water from the water heater
module
1110 and route the heated water through the heat exchanger 300. The heat
exchanger 300
transfers heat from the water to the air of the hydro-furnace module 1130,
such that heated return
air can be supplied by the blower 325. The heat exchanger can comprise a core
body 301 with a
box-like shape and core tubing 310.
In embodiments, the blower 325 can have a suction portion 326 and a blower
port 327 to
move the air. Alternatively, the ports can be reversed, or a different type of
blower 325 can be
used, as desired.
Within the core body 301 of the heat exchanger 300, a plurality of spaced
apart fins can
be provided. The fins can be closely spaced or loosely spaced inside the core
body 301 to form
baffles or channels for the flow of air through the heat exchanger 300
generated by the moving
of air by the blower 325. The number of fins can depend on the desired heat
exchange rate by
convection, conduction, and radiation exchanging with the interior run line of
the core tubing
310.
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The core tubing 310 passes through the fins and wherein U-shaped returns are
provided
on opposite exterior surfaces of the core body 301 to connect the parallel
tubing sections in a
serpentine fashion within the interior space of the heat exchanger 300. The
number of fins and
the total tubing length passing inside the heat exchanger 300 can be selected
to control the
residual time of water travelling through the heat exchanger 300 and the
amount of heat
transferring directly from the core tubing 310 to the fins and then to the
air.
In one embodiment, the core tubing 310 and the fins, are made from a highly
conductive
material, such as copper, brass, or their alloys.
In this way, the blower 325 can move air over the heat exchanger 300 to
transfer the heat
from the water to the air of the hydro-furnace module 1130. The heated air can
then be provided
through air vents 107 from the housing 1132 of the hydro-furnace module 1130
to the interior of
the RV. The air vents can be provided to the housing 1132 such that there is
necessarily some
circulation of heated air inside the housing 1132 of the hydro-furnace module
1130 as the blower
325 operates. As such, the temperature of the air inside the house 1132 can be
higher than
ambient.
The present disclosure provides a modular RV water heating and furnace system
having a
heat exchanger housing that houses a heat exchanger and a burner, a hydro-
furnace housing that
houses a heater core and a blower, and a tank housing that houses a storage
tank.
The burner provides heat to the heat exchanger and the heat exchanger heats
water
flowing therethrough it.
The blower moves air through the heater core, which is provided with the
heated water
from the heat exchanger.
The present disclosure provides a modular RV water heating and furnace system
having a
water heater, a heat exchanger, and a storage tank. The water heater heats
input water and
outputs the heated water. The heated water is then provided to the heat
exchanger. The heat
exchanger attached to a blower, which moves air through the heat exchanger,
thereby warming
the air. The heated water is then provided through a one-way valve from the
heat exchanger to a
storage tank. The heated water is then provided from a second one-way valve to
a pump and a
solenoid valve for circulation back to the water heater.
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Methods of making the hydro-furnace systems, of using the hydro-furnace
systems, and
of installing the hydro-furnace systems as described herein are within the
scope of the present
invention.
Although limited embodiments of the hydro-furnace 100 for RV assemblies and
their
components have been specifically described and illustrated herein, many
modifications and
variations will be apparent to those skilled in the art. Accordingly, it is to
be understood that the
hydro-furnace 100 assemblies and their components constructed according to
principles of the
disclosed device, system, and method may be embodied other than as
specifically described
herein. The disclosure is also defined in the following claims.
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