Note: Descriptions are shown in the official language in which they were submitted.
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DIRECT POWER VENTED WATER HEATER
Background of the Invention
The present invention relates generally to a power-
vented water heater. The power venting is provided by a
blower which induces a draft for ~he flue gases generated by
the water heater. The heater utilizes a direct through-the-
wall vent design thereby obviating the need for a chimney~
The heater also utilizes a flexible flue gas exhaust line
providing the advantage of installation flexibility.
Description of the Prior Ar~
U.S. Patent No. 4,262,608 to Jackson discloses a water
heater having a draft hood and a flue pipe leading to an air
manifold. This patent further discloses a blower positioned
immediately downstream from the manifold. The blower has a
dual function, namely to force the exhaust gases out through
the exhaust pipe and simultaneously bring in fresh outside
air through an intake pipe. This type of system is generally
referred to as a "balanced flue" system.
U.S. Patent No. 49424,792 to Shimek et al dis~loses a
2Q wood burning furnace utilizing a direct vent design. The
direct vent utilizes an induced draft blower installed on
the exterior of the wall which operates to draw flue gases
through the flue pipe. This patent further discloses a
pivoting cap at the vent outlet.
``U.S. Patent No. 4,424,792 i8 directed primarily to a
device for cooling the hot flue gases be~ore they pass
through the exterior wall by mixing them with cool outside
air just before venting.
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Other prior art patents include U.S. Patent Nos. 3,601,09g;
1,859,745; 3,759,230; 2,563,817; 4,357,909; 1,g35,919i
1,643,~59; 1,713,442; 1,826,748; 2,348,950; 3,280~774;
4,303,042; 3,492,972; 4J487~137; Re 31,256; 4,254,759;
3,782,303.
The water heaters of the prior art have typically
relied upon the natural draft of the hot flue gases, rising
~hrough the flue pipe(s) of a water heater and being vented
into a chimney. Because ~hese gases were warmer than the
l~ surrounding air, they tended to naturally rise. However,
with this type of design, the positioning of the water tank
was somewhat limited since for practical reasons it had to
be placed close to the chimney. Thusj it is an object of
the present invention to provide a water heater which need
not be vented into a chimney, ~hereby providing greater
installation flexibility.
It is another object of the present invention to provide
a water heater venting design which needs no chimney. This
is important from several cost reduction standpoints.
~ First, in new house construction, homes may be constructed
without a chimney, thereby significan~ly lowering the cost
of a new home. Secondly, during the so called "gas moratorium"
of the 1950's and 1960's, many houses were built for all-
electric heating, and therefore have no chimney. Now that
~5 natural gas has become comparatively much less expensive,
there is a desire by many "all-electric" home owners to
convert to natural gas heatingO Thus, it is an important
object of the present invention to provîde a water heater
1ue gas venting design adaptable to conversions from all
electric heating.
It is a further object of the present invention to
provide a direct through-the-wall vent design adaptable to
~ high velocity outside winds.
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It is another important object of the prei3en-t invention
to provide a flexible connector pipe between the water
heater and the direct vent which is air tight, flexible, and
which operates at a lower temperature thereby reducing the
risk of burn injuries, and obviating condensation problems.
These and other important objec~s of the present invention
will become readily apparent from the description appearing
hereinafter.
Summary _of the Invention
10 A direct power vented water heater having a collection
chamber positioned above the water tank, the collection
chamber being in fluid communication with an exhaust blower
and a flue gas exhaust line, is provided. The blower conveys
the flue gases through the exhaust line to a direct through-
the-wall vent. Water heater control means are provided for
sensing the temperature of the water in the tank and controlling
the amount of fuel supplied to the burner in response thereto.
The control means activates the exhaust blower when the fuel
is being supplied to the burner but deactivates the exhaust
blower when the fuel supply to the burner is cut. The
control means also interupts the supply of fuel to the
burner in the event that either a total or partial blockage
of the flue gas exhaust occurs.
Brief Description of the Drawings
~5 Fig. 1 is a side view9 shown partly in section, of a
water heater illustrating one embodiment of the presen~
invention.
Fig. 2 is a side view, shown partly in section, of a
water heater illustrating a isecond embodiment of the present
invention-
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Fig. 3 is a side view, shown partly in section, of a
water heater illustrating a third "balanced flue" embodiment
of the present invention.
Fig. 4 is a side view, shown partly in section, of one
baffled flue pipe design with may be utilized with certain
embodiments of the present inventionO
Fig. 5 is a sectional view of the baffled flue pipe
illustrated in Fig. 4 taken along line V-V.
Fig. 6 is a side sectional view of a direct through-
the-wall vent according to one embodimen~ of the present
invention.
Fig. 7 comprises two schematic wiring diagrams of one
embodiment of the burner and blower control apparatus utilized
in the present invention.
Fig. 8 is a side view, shown partly in section, of an
alternate flue pipe, collector box and blower assembly which
may be used in place of the assembly illustrated in Fig. 2.
Fig. 9 is a side view, shown partly in section, of a
removable flue pipe baffle which may be used in certain
embodiments of the present invention.
Although specific forms of apparatus embodying the
invention have been selected for illustration in the drawings,
and although specific terminology -~ill be resorted to in
describing those form~ in the specification which follows,
their use is not intended to define or to limit the scope of
the invention, which is defined in the appended claims.
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Description of the Prefe d Embodiments
Referring to the drawings wherein llke reference numerals
refer to the same features in the several drawlngs, and
especially referring to Fig. 1, there is shown a water
heater 10. Heater 10 comprises a water tank 11 having a
tank head 12 and a tank bottom 13. Extending vertically
be~ween tank head 12 and bottom 13 and passing ~hrough the
interior of tank 11 is flue pipe 17 having internal baffling
18.
An alternate baffle construction which may be utilized
in the embodiment of water heater 10 illustrated in Fig. 1
is shown in Fig. 9. In this alternate embodiment, baffle 80
com~rises a divider 81 having a length corresponding to the
length of flue pipe 17 and a width which is substantially
the same as the inner diameter of flue pipe 17. Thus, when
baffle 80 is placed within flue pipe 17, divider 81 divides
~he interior of flue pipe 17 into two sections. Attached to
divider 81 are a plurality of plates 83 having an L shaped
cross section and having a semicircular shape so that the
~0 outer edge of plate 83 is in substantially continuous contact
with the inner surface of flue pipe 17. Each of the plates
83 is fixedly attached to divider 81 and rests against a
triangular shaped support 84. Divider 81 is provided with a
plurality of openings 82 between adjacent plates 83. All of
divider 81, plates 83 and supports 84 are typically constructed
of sheet metal. Baffle 80 is simply placed within flue pipe
17 by inserting in an upward direction. The bottom sides of
plates 83 are preferably not fixedly attached to the top
sides of supports 84. In this way, baffle 80 can be easily
removed from flue pipe 17 for cleaning purpose~ simply by
pulling out divider 81 in a downward direction. When the
baffle 80 is in place within flue pipe 17, the flue gases
passing upwardly within pipe 17 will follow the twisted path
as shown by the arrows in Fig. 9
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Surrounding the side wall.s of tank 11 is an insulating
layer 14 typically composed of fiberglass or polyurethane
foam~ Surrounding insulation layer 14 is outer jacket 15.
Positioned beneath tank bottom 13 is combustion chamber 20
housing gas burner 21, a pilot line 24 and gas supply line
23. A gas valve and a thermocouple circuit (not shown) is
provided within control means 25 in a kno~m manner. An
emersion rod 22 is provided in order to measure the temperature
of the water in the tank 11. A thermostat is provided
within the control means 25, as will be described in more
detail hereinafter, to regulate the operation of the burner
21.
Positioned above tank head 12 is an insulating layer 26
and a Jacket top 27. Draft diverter 29 is positioned above
jacket top 27 and centered over, but spaced apart from, the
top end of flue pipe 17. Diverter 29 is connected to collector
box 30 at opening 31. Collector box 30 is a container
typically constructed of sheet metal. Thus, diverter 29
connects with opening 31 to direct the flue gases rising
from flue pipe 17 into collector box 30.
Blower 34 is connected to collector box 30 through
opening 32. When activated, blower 34 draws the gases
within ~ollector box 30 through opening 32 and blows them
through the blower outlet 36 into flexible conduit 37.
Blower 34 is typically an electric powered blower having a
power cord 35.
Provided on the draft hood 29 is a thermostat 33 which
is operatively connected to the blower 34 by means of the
control means 25. In the event that there is a blockage in
the flue gas exhaust line downstream from the draft hood 29,
the rising flue gases will spill out ~rom under the draft
hood and be sensed by thermostat 33. Thermostat 33 is
typically set to signal control means 25 in the event
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the sensed temperature rises above about 1 80Fo Thermostat
33, sensing the spillage of the hot flue gases from underneath
the draft hood 29, will activate control means 25 to shut
off the supply of fuel to burner 21. In addition, thermostat
33 will also deactivate blower 34 at this time.
Also provided within the shroud of blower 34 is a
second thermostat 75 which is also typically set to signal
control means 25 in the event that the temperature rises
above about 180F. This dual (i.e. ~hermosta~s 33 and 75)
safety circuit system is especially preferred from an operating
standpoint. In the event that there is either a total
blockage of the flue gas exhaust, or if the blower 34 fails
to operate, thermostat 33 quickly senses the hot flue gases
spilling out from under diverter 29 and quickly signals
control means 25 to cut off the supply of gas to burner 21.
In the alternative, in the event of only a partial blockage
of the flue gas exhaust line, thermostat 75 is the first to
sense the risin~ flue gas temperature and quickly signals
control means 25 to cut off the supply of gas to burner 21.
Turning now to Fig. 6 of the drawings, there is shown
an embodiment of a direct through-the-wall vent which is
connected ~o the downstream end of flexible pipe 37. The
term "through-the-wall" encompasses direct vents of the type
which convey flue gases from an interior portion of a building
or structure to an exterior portion of a building or structure
for venting. Thus, for example, the term "through-the-wall"
encompasses walls of all types, regardless of structure or
composition~ as well as other structures such as roofs and
ceilings, as long as one side of the structure aces an
interior space and the other side of the structure faces an
exterior space into which the flue gases will be vented. In
Fig. 6 there i9 shown a typical through the wall vent 40
mounted within a cylindrical hole 41 passing through wall
39. Within hole 41 is positioned a metal sleeve 42. An
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inner sleeve 44 having a face plate 45 is slid into the
interior end of sleeve 42. Furthermore, face plate 45 has a
circular hole 46 therein through which extends the interior
end of conduit 43. Similarly, sleeve 42 ha~ an exterior
face plate 48 with a circular hole 47 through which the
exterior end of conduit 43 extends. In this way, conduit 43
is annularly spaced wi~hin sleeve 42. Face plates 45, 48
are secured to the wall 39 by conventional means. Flexible
pipe 37 is secured to the interior end of conduit ~3 with a
clamp 38.
Hingedly mounted on face plate 48 is flapper plate 50.
A hinge 49 is provided for this purpose. Flapper plate 50
normally rests in a vertical poæition thereby acting as a
damper when blower 34 is in an off cycle. However, when
flue gases are flowing through flexible pipe 37 and conduit
43, the flapper plate 50 swings open to allow venting of the
flue gases. A stationary plate 51 may also be provided in
order to provide better protection against back flow in the
conduit 43 and flexible conduit 37 in the event of high
winds and the like. In the event that winds are blowing
against the stationary plate 51 as indicated by the arrows,
the flow of air is directed downwardly upon striking the
angled plate 51. Thls downward flow of air causes a low
pressure region S3 to form just below plate 51. This low
pressure region 63 helps to draw the flue gases out of the
space behind plate 51. Thus, stationary plate 51 assures
proper ventilation of the flue gases even in the case of
high velocity winds directed into the vent 40.
Flexible pipe 37 is preferably constructed from a wire
reinforced EPDM (ethylene propylene diene monomer) rubber,
which is airtight and both bendable and extendable. Flexible
pipe 27 preferably has a continuous operating temperature
rating above 200F, more preferably above 250F. Although
the length of the flexible pipe 37 ls not limited to any
particular range, in most applications a length within the
range of 6-15 feet is sufficient.
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Because draft diverter 29 is spaced apart from the top
end of flue pipe 17, the suction created by blower 34 draws
not only the hot flue gases into collec~or box 30 but also
draws some of the surrounding room air under diverter 29
into collector box 30. Thus, the hot flue gases are "diluted"
by mixture ~ith the ambient air. After this dilution, the
gases pumped through flexible tube 37 are typically in the
range of about l50-180F. At such low temperatures~ condensation
problems within flexible pipe 37 are practically eliminated.
In addition, there is a much less likelihood of burn injuries
~o persons coming into contact with flexible pipe 37 because
of this temperature dilution.
Referring now to Figures 2, 4 and 5, there is illustrated
a second embodiment of the present invention wherein the
blower 34 supplies combustion air to burner 53 while at the
same time blowing the flue gases through flexible pipe 37
and out the direct vent 40. The heater 9 illustrated in
Fig. 2 has a substantially airtight combustion chamber 20
Combustion air for burner 53 is provided by blower 34 and
baffled tube 52. Blower outlet 36 is fluidly connected to
the interior space 66 within baffled tube 52. When the
blower is on, air is drawn from the ~pace surrounding blower
34 and blown through the interior 66 of baffled tube 52.
Baffled tube 52 extends into the lower portion of combustion
chamber 20. Burner 53, having a l'donut-shapedll configuration,
wraps around the lower end of tube 52. Combustion air flows
out the lower end of tube 52 as shown by the arrows and
mi~es with the fuel gas supplied to burner 53 allowing
combustion to take place. Because chamber 20 is provided
with appropriate seals to make it substantially airtight,
the combustion flue gases are ~orced to flow upwardly within
flue pipe 17 through the segmented exterior space 65~
The configuration of baffled tube 52 within flue pipe
17 is clearly illustrated in Figs. 4 and 5. The baffled
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tube 52 is provided with a plurality of 6piral ridges 67
along its circumference. Ridges 67 are in contact with the
inside of flue pipe 17, thereby dividing the space 65 into a
plurality of spiral pathways~
As the cool room air is forced through the interior
space 66 it is prewarmed by countercurrent flow with the hot
combustion flue gases passing upwardly through the segmented
space 65. This allows for more efficient combustion of the
fuel gases at burner 53.
At the top end of flue pipe 17, the exterior space 65
is open to the interior of collector box 30 through opening
31. Collector box 30 also has opening 32 connected to
flexible pipe 37. In this way, the hot flue gases pass from
space 65 into collector box 30 and finally into flexible
pipe 37 whereby they flow out a direct vent 40.
Fig. 8 illustrates an alternate design of the collector
box 30, flue pipe 17 and blower 34 which may be used with
the heater 9 illustrated in Fig. 2. In this alternate
design, blower 34 is positioned downstream from collector
box 30 and blows the flue gases out the blower outlet 36
through flexible pipe 37. A pipe 62 is provided between
opening 32 and blower 34. Thus, blower 34 provides suction
to convey the flue gases from exterior space 65 into collector
box 30, through pipe 62 and finally through blower 34 and
~5 flexible pipe 37. In this embodiment, tube 52 extends all
the way through collector box 30 and opens at the top thereof.
Bec~use the combustion chamber 20 is airtight, the operation
of blower 34 ~auses surrounding room air to be conveyed down
the interior space 66 as shown by the arrows in order to
provide combustion air to the burner 53.
Fig. 3 illustrates a "balanced flue" version of the
water heater 9 illustrated in Fi~. 2. In the balanced flue
design, blower 34 is provided with an air inlet pipe 61
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which extends to a space outside the building. In this way7
combustion air is drawn by blower 34 from the outside of the
building through inlet pipe 61 and blown into the in~erior
space 65. In this design, the water heater 9 is totally
"closed" with respect to the room environment since the
combustion air is drawn from outside the building and the
flue gases are vented directly outside the building~
R~ferring to Fig. 7, there is il]ustrated schematically
one embodiment of a blower and burner control circuitry
which may be utilized with the present invention. There is
illustrated a wiring diagram 70 as well as a ladder circuit
diagram. Power is provided by a 115 power supply 71. A
relay contact 72 is provided to control the supply of power
to blower 34. Thermostat 75, within the shroud of blower
34, provides an advance sensing control in the event that
there is a partial blockage in the flow of ~lue gases downstream
from blower outlet 36. Both thermostat 75 and thermostat 33
are operatively connected to control means 25 to shut off
the flow of gas to the burner in the event of any blockage
~ or restriction of the outward flow of flue gases through
flexible pipe 37.
Control means 25 is operatively connec~ed to a pressure
`switch 73 through a gas line 74. In the event that the
thermostat within control means 25 calls for the burner to
be activated, control means 25 opens a valve thereby causing
gas to flow through gas supply line 23b as well as gas line
74. The flow of gas through line 74 causes pressure switch
73 to connect thereby supplying power to blower 34, This
ensures that blower 34 will be operating when the burner is
turned on.
Similarly, when the thermostat indicates that the
temperature of the water within tank 11 has reached a
desired level, control means 25 shuts off the supply of gas
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to gas supply line 23b and gas line 74. Thus, pressure
switch 73 is disconnected and interrupts the supply of power
to blower 34.
Although this invention has been described in the
specification with reference to specific forms thereof, it
will be appreciated that a wide variety of equivalents may
be substituted all without departing from the spirit and
scope of ~he invention, which is defined in the appended
claims.
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