Note: Descriptions are shown in the official language in which they were submitted.
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The present invention is directed to a blower
override system and control for forced air heating systems
wherein a relay, activated by the ignition and supply
function of fuel to the burner as, for example, tripped by
a thermostat, starts the blower and extends performance of
the blower until the burner is turned off and then, via a
time delay, continues the blower function for a selected
time period. The same unit is operable with air conditioning
blower units with equivalent savings.
No interference with regular controls is re~uired
and the regular controls serve as a fail-safe back up. The
regular controls alone trip the blower at a preset
temperature level in the plenum or at the thermostat and
results in substantial heat loss to the stack, both before
and after the heat cycle. The re~ular controls stop the
plenum blower with the stopping of the burner. The present
invention is directed to a device which starts the blower
at the onset of heat and continues the blower operation for
a ti~e interval after the burner is turned off.
Bac~round of the Invention
In modern furnaces of the forced air heating type
(oil, gas, electric, hot water, and steam), it is usual for
the controls to initiate the burner or heater function and
thereafter, upon achieving a thermal set condition, for
example in the plenum or heat ducts, to -then initiate the
blower runction. The heat cycle continues until the house
thermostats reach the upper set point and the cont~ols stop
the hot air blower and the heat source or furnace. Actuall~v,
heat is increasing in the plenum over ambient air conditions
substantially at the instant of application of the heat source
as, for example, from combustion in the furnace and the heat
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is reslduallv retained in the plenum or heat exchangers
after the furnace is turned off and until the heat surfaces
reach ambient temperatures.
Regular controls do not treat the situation at
start-up by starting the warm air blower and do not treat
the situation, as in the present invention, to strip the
residual heat after furnace shutdown. Without the present
invention, substantial loss of available heat occurs directly
up the chimney and as a consequence causes sucking of
combustion air into the house or area heated upon
commencement of combustion and before commencement of the
plenum blower.
Investigations conducted to determine the amount
of heat saving have been extraordinarily encouraging and when
the contribution of the present invention is compared against
regular controls r the forced air heating systems in which the
present invention has been utiliæecl have demonstrated
substantial savings of heat and consequent economy to the users.
As applied to gas furnaces, the electric consumption held
level and a gas savings of about 27,000 cubic feet resulted
in a heating season. Maximum savings is realiæed when the
- increase in unit costs of gas and oil are contemplated.
This is also true because the gradual heat rise at the start
of the cycle and the relatively high thermal residuals at
shutdown are utilized. The system is applicable to gas
; fired, oil fired, and electric warm air furnaces as well and
on the basis of these findings it is possible to anticipate
a fuel savings of between about seven to thirty percent
over the experiences of regular controls of varying
sophistication. These accomplishments re~uire no physical
alteration of e~isting forced air heating plants and with the
present invention is achieved by simple addition to e~isting
controls.
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Prior Art Dis-tinguished
In 1~77 the United States Letters Patent 4,013,219
issued to James Jacobson and in that struccure a thermostat
was modified to include a timer. This device was a manually
actuatable timer and its objective was an override for all
controls which, then, required manual reset.
The United ~tates Letters Patent 4,0~0,663 to Ulrich
Bonne, e-t al is directed to a fan control functioning on the
basis of a heat differential between plenum and the return
air temperature.
None of the known devices provide an automatic
blower control system capable of preventing heat loss at th~e
ends of a heating cycle in forced air systems.
While both prior art systems of control seek to
achieve an energv savings, they at-tack the prohlem of juggling
-the thermal input based upon selected operating optimums or
in accord with manual selection of applications of heat.
Neither propose a simple and automatic system and control
applicable to all forced air systems and where the regular
controls may remain in-tact and perform their regular function.
Accordingly, the principal object of the present
invention is to provide an energy conserving device attachable
to existing furnace or heating system controls of the forced
air type which automatically function.
Another object is to teach energy savers of the
control of energy loss via the blower and permitting the
blower to start on introduction of combustion gases or heat
source to the surfaces over which the blower operates.
Other objects, including simplicity, ease of repair
and rèpeti-tive accuracy, will be apparent as the application
proceeds.
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In accordance with the present invention there
is provided an energy conserving control for a thermal
source which is connected in parallel around existing
thermostatic controls and which acts on the blower circuit.
The control comprises an electric blower activating circuit
connected to the blower and activating the blower upon
initiation of the thermal source. There is also a relay
connected in parallel to the thermal source and starts the
blower at initiation o~ the heat source. Finally, a
selec-tively adjustable time delay is connected to the blower
circuit upon discontinuance of the thermal source.
In general, the present invention is an
override control for forced air heating and air conditioning
systems and which exercises control over the
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air blower which delivers warm or cool air. The greatest
saving of energy is in the heating field, but energy saving is
apparent in air conditioning cycles as well. The control and
system comprises an electric activating circuit which s-tarts
the blower when the heat media (as a burner) or cooling media
(as a compressor or thermal source) is activated. The
activating circuit, as applied to forced warm air, is in
parallel with an override relay so that upon actuation of the
activating circuit by normal controls, the override relay is
activated and starts a warm air blower. A time delay relay
which acts upon the override relay is connected for
actuation upon cessation of flow of heat media source and
provides an adjustable time interyal in prevention of
deactivation of the activating relay after disco,ntinuance
of the heat or thermal source., This keeps th,e blo~er working
for the timed interval and therea~fter tke ti,me delay relay
deactivates the blower from moving warmed air. While
applicable to forced cold air systems, the structure and
control can be appreciated easiest where the heat media source
is considered as a burner. Then the system is an override
control for forced air and in control of a warm air blower
having an electric thermal control circuit. An activating
circuit initiated by the starting of the burner is provided.
An override relay is connected in parallel to the burner
circuit and this is activated when the burner circuit is
activated and starts a warm air blower in the forced air
system. A time delay element acts upon the override relay
in adjustable timed interval in prevention of deac-tivation
of the rela~ after discontinuing the burner performance.
The time delay deactiva-tes the warm air blower upon completion
of the timed interval after discontinuance of the thermal
source.
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While heat installations are referred to, the
devices and system of the present invention are equally
useful in distribu-ting cold, as from an air conditioner
device, so that the blower is started with the compressor or
cold thermal source flow and continues for a timed interval
beyond cessation of movement of the cooling media~
In the Drawinys
Figure 1 is a schematic block diagram of an
override control in a conventional gas or oil fired furnace
and functions wi-th regular controls to achieve the fuel
saving result of the present invention.
Figure 2 is a perspective view of the control of
the present invention in a simple circuit box.
Figure 3 is a front elevation view of the embodiment
of the invention seen in Figure 2.
Figure 4 is a top plan view of the structure
of Figure 3.
SpeciEic Description
Referring with first particularity to the
Figure 1, there is schematically shown the location of the
energy saving overrlde blower control system 11 and it is
shown connected to an air conditioning cooling system 12
and to a heating system 130 The arrangement is characteristic
- of combining heat and air conditioning installations using
common controls. The compressor 14 may be regarded as the
source of cooling -thermal energy. The coolant media 15 as,
for example, ammonia, brine or other coolant compounds pass
from the compressor 14 and into the coolant coils 16 with
ultimate return to the compressor 14~ A coolant blower or fan
17 forces air over the coil 16 and into the space such as
a dwelling where the cool air drops the temperature and returns
to the fan or blower 17 for recirculation. The cooling
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thermostat 1~ is a part of the regular controls 19 signalling
within appropriate opera-ting range the energization of
the compressor 14. At its lower set point, the cooling
thermostat shuts off the compressor 14 and with it the fan or
blower 17. Usin~ regular controls 19, the fan 17 is initiated
when the compressor turns on and runs until the thermal
condition 20 achieves a set point. Using ordinary or regular
controls 19, the cooling system does not commence circulation
until the set point is achieved. In the heating system 13
served by the regular controls 19, the thermostat 21 (heat)
signals the demand for heat and the heat source, such as
burner 22 (gas, oil, electricity), is started in the furnace
23 as by combustion and the exhaust combustion gases travel
from the stack and out of the house or heated enclosure. Air
in support of the combustion enters the burner 22 from
ambient or ou-tside air. The heat generated by the combustion
in furnace 23 is exchanged to air ~ia the exchange surfaces of
the ~lenum 25. when the plenum 25 reaches a selected heat
set point, the blower or fan 26 is started which pumps the
warmed air into the house or heated enclosure. The starting
condition using regular controls 19 is the thermal set point
established in the plenum 25O Using the regular controls 19,
the function of the heating and the cooling are as described
until the energy saving override blower control 11 for forced
air systems with time delay is superimposed. The override
blower control 11 with time delay re~ay is activated when
the therrnal source, such as compressor 14 or burner 22, is
star-ted and this starts the blowers or fans 17 and 26 in accord
with the commencement of the regular controls 19 as by the
heating thermostat 21 or the cooling thermostat 18 responding
to the set conditions in the home or enclosure. The blowers
17 or 26 continue to run until the time delay relay in the
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o~erride control 11 adds its timed in-terval of performance
(usually selected between two and five minutes) after the
compressor 14 or burner 22 is stopped. This strips the
residual heat or cold and distributes it in the house or
enclosure beyond the shutdown called for by the thermostats
18 and 21. An evener thermal condition is brought about and
the energy which would otherwise waste to an external
environment is utilized and the interval between burner
activations is extended.
The override control 11 is better understood by
examining its simple construction as set out in the Figure 2.
The entire control 11 is enclosed in a simple control box
30. The box 30 is a metal Underwriter approved enclosure
with a hinged cover 31 and with knock-out windows on all sides
to suit varied installation situations. A channel shaped
chassis platform 32 is slidably positioned in the box 30 in
whatever position is convenient since the box 30 is
rectan~ular and of a depth equal to -the depth of the platform
32 allowing inversion o~ the box 30 to shift the hinged cover
to left or right openings. Eight colored leads extend from
the box 30 and are color coded to their end uses ~or ease
of field installation. The leads (Figure 4) are connected
to the control elements as will be appreciated as the
description proceeds~
Centrally connected to the chassis platform 32 is
an 11 pin octal socket 33 coded 6 x 156 and rated at 10 amps
and 300 volts alternating current. It is Underwriter
Laboratory Listed as E40944. The socket 33 provides the 11
pin octal receptacle for plug-in enclosed (off delay~ double
pole, double throw relay 34 of the adjustable delay type
adjustable between 2 and 3Q0 seconds (5 minutes) coded 6 x 155
and bearing Underwriter Laboratory Listing E40944.
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Flanking t~e time ~elay relay 34 are the oYerride
relays 35 and 36. These are single pole do~ble throw type
relays and are coded 5 x 334and 15 x 835,respectively, at 13
amps and relay 35 operates at 24 volts for control of a gas
valve or for a 24 volt air çonditioning relay and bears
Underwriter Laboratory Listing E35623G. Relay 36 operates at
120 volts alternating curren~ and is for a 1lO volt alterna,ting
current ~as power burner and oil relays~ The relay 36 also
~ears the Underwriter Laboratory Listing E56730. These r~lays
35 and 36 are regarded as the override relays and serve to
start the fans or blowers 17 and 26 when t~e regular controls
start the air conditioning or burner units, respectively.
While both 24 volt and 120 volt override relays are provided,
a selection will have to be made according to what the
actuating circuit providesO
~ dentical 11 pin sQc~etS 35a and 35b pro~ide tke
socket mountin~ means ,for the plug-in relays 35 and 36~
respectively. The sockets 35a and 35b are coded 5 x 853
rated at 10 amperes and 300 ~olts alt,ernatin~g current and,
?0 bear Underwriter ~aboratory ~isti~ E409~4~
In th,e compa,ct arrangement, s~own, as where a heating
and air condition,ing unit are bo~t,~ ser~ed by the same override
blowe~ control unit 11~ t,he tim,e delay re,la~ 34 i,s in the
mounting socket 33 and the socket 33 is sec~ed firmly to the
ckassis 32. The flanking sockets 3Sa and 35b are generally
in adjacent aligned rela~ion to t~e socket 33 and are secured
to the c~assis 32~
In Figure 3 the override blower control is in~icated
as secured in place in -the control box 30, as viewed upon
opening t~e box.
sy reference to Figure 4, factory wiring as between
the units 34 and 35 and 36 is ins-talled as indicated and these
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leads in heavy ~ine are preferably fixed at the factary
in avoidance of tampering. ~'hese leads interrelate the
relays 35 and 36 to the time delay relay 34 so that the time
delay relay assures that the blowers 17 and 26 will function
at start of the compressor 14 or burner 22 and will continue
that functioning until the timed interval of the relay 24 is
complete.
In the Fi~ure 4 the leads are shown (as colox
coded) extending from the rear of the platform 32 a,nd fxom the
interlocked pin socket receptacles 35a and 35b and the central
tirne delay relay mounting socket 34~ As will be appreciated,
the override relays 35 and 36 are easily removed and ~eplaced
for servicing and the time delay element 34 is also ea,sily
removed and replaced as necessaryi. The wiring remains intact
and the interval timing is imposed on th,e ~owers afte~ the
thermal source (hea,ter or air conditioner) has been stopped~
After the timed interval, the b~owers a~e sh~u,t down bu~ the
heat has been stri~pe~ an~ delivered to the living space to
avoid heat loss up the ckimney and the cold has been
normalized by supplying the residual sooling to the served
space in the home or use premi~es at a substant,ial savings of
- energy~
In Figure 4 the ove,rride blower control 11 is
indicated as applied to a furnace a,nd an, air con~iti~on,in~ unit
in control over bhe blowers of each. When control is sought
only over one o-E -the uni-ts, then only one relay need be used.
The time delay relay 34 is connected to a so~rce of powe,r
serving the furnace and/or the air conditioner and including
the blowers therefor. In bo-th, the distribution blowers come
on whei~ the burner and/or compressor s-tarts. Then, when the
thermal set points have been achieved, the blowers stop with
cessation of heating or cooling. At that poin-t, the time delay
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relay 3~ connected to power ahead of the furnace 23 or air
conditioner 12 acts upon the relays 35 and 36 and holding
the function of the blowers.
By reference to Figure 4, the brown wires or leads
connecting the relays 34, 35 and 36 are factory installed and,
as shown, both the heating unit relay and the air condition
relay are provided. If only override control over the air
conditioner or heating is required, then one of the relays 35
and 36 may be eliminated.
The two red wires are useable cross the burner or
gas valve relay 36 if a gas valve relay is used in the heating
circuit or otherwise to the burner ignition if oil or electric
heat are used. It is, of course, necessary to determine if
the voltage is 110 volts or 24 volts.
The two blue wires are across the air conditioning
relay 35~
The two yellow wires or leads are to the terminals
across the blower control in the regular controls 19.
The lead colored black is attached to the hot line
oE the furnace or thermal system served and the white wire is
to the ground of the furnace or thermal system served. Thus
coded, field installation is vastly simplified and adapts the
override control 11 to myriad control circuits as found in
heat~ng and air conditioning installation. Basically the
override control 11 is wired in parallel.
Where plural speed blower or fan operation is
desired, it will be appreciated that additional override
controls 11 may be required Eor each opera-tional level.
Noteworthy is the point that the structure of the
present invention, once installed, is adjustable via the time
delay relay to a selected operating period after cessation of
the -thermal source by reason of the selected holdover period
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in the time delay relay 34. The optimum time selected
should be that period of time where the thermal residual.s are
fully delivered to the dwelling space or.use space. Energy
saving economies are obvious since the thermal residuals are
used rather than exhausted to external atmosphere~
No changes are required in the existing control
wiring~
Having thus described my invention and one
operative embodiment thereof, those skilled in the art will
appreciate changes, modifications and irnprovements therein
and such changes, modifications and improvements are intended
to be embodied herein limited only by the scope of my
hereinafter appended claims. As will be appreciated, the
electrical components thus described may be substituted for
by suitable electronLc or solid state equivalents without
depar-ture from the spirit of the present invention and
such modification is contemplated in my hereinafter appended
claims.
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