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US 5,326,026 AGranted
Energy and peak-load conserving thermostat and method with controlled deadband
AssigneeArnold D. Berkeley
InventorsDonald E. Jefferson, Arnold D. Berkeley
Life of this patent
Estimating the term…
Abstract
A thermostat is disclosed for controlling a heating system, particularly a forced hot-air furnace, so as to improve fuel efficiency and decrease peak fuel load. The thermostat controls the length of fuel-on cycles, so that the heat exchanger of the furnace is not saturated. A wide deadband (approximately 3.degree. F.) for the thermostat further aids in lessening fuel usage. Forced air operation continues for a secondary-delivery period immediately after the thermostat turns the furnace off, thereby extracting additional heat from the heat exchanger and ductwork, but the length of the secondary-delivery period is limited so that the heat exchanger does not cool off beyond a predetermined amount.
Claims20
A fuel-conserving thermostat for controlling operation of a heating system that consumes fuel during a fuel-on interval and heats a defined space, thereby increasing a space temperature of said space;
- said space being thermally conductive to an ambient, whereby a heat flux occurs from said space to said ambient;
- said heating system comprising:
- heating means for providing heat during said fuel-on interval;
- delivery means for delivering heat to said space during a delivery interval, whereby a heat flux occurs from said heating means to said space during said delivery interval;
- a heat exchanger;
- signal-receiving means, coupling said thermostat and said heating means, for:
- initiating one of said fuel-on intervals, which begins when said signal-receiving means receives a FUEL=1 signal from said thermostat;
- terminating said fuel-on interval and initiating a fuel-off interval in which said furnace does not consume fuel, said fuel-off interval beginning when said signal-receiving means receives a FUEL=0 signal from said thermostat;
- initiating one of said delivery intervals, which begins when said signal-receiving means receives a DELY=1 signal from said thermostat;
- and
- terminating said delivery interval and initiating a nondelivery interval in which said furnace does not deliver heat to said space, said nondelivery interval beginning when said signal-receiving means receives a DELY=0 signal from said thermostat;
- said thermostat including:
- a timer providing timing signals;
- a temperature sensor having means for providing a space-temperature signal representative of said space temperature;
- means for providing a set-point-temperature signal representative of a set-point temperature;
- and
- means for providing said FUEL=0, FUEL=1, DELY=0, and DELY=1 signals;
- said thermostat further comprising:
- means for providing a maximum-on signal representative of a maximum fuel-on interval, where said maximum-on signal is provided by signal generating means for providing a signal representative of how long said heat exchanger can operate during a fuel-on interval in a linear mode before its mode of operation becomes nonlinear;
- and
- burn-control means for causing a fuel-on interval to have a duration of no longer than said maximum fuel-on interval;
- and
- said temperature sensor having coupled thereto means for predetermining a deadband of from 1 to 4 degrees Fahrenheit for said temperature sensor.
20 more elements
A fuel-conserving thermostat for controlling operation of a heating system that consumes fuel during a fuel-on interval and heats a defined space, thereby increasing a space temperature of said space;
- said space being thermally conductive to an ambient, whereby a heat flux occurs from said space to said ambient;
- said heating system comprising:
- heating means for providing heat during said fuel-on interval;
- delivery means for delivering heat to said space during a delivery interval, whereby a heat flux occurs from said heating means to said space during said delivery interval, said delivery interval consisting of a primary-delivery interval and a secondary-delivery interval, where:
- said primary-delivery interval generally coincides with a fuel-on interval and ends when said fuel-on interval ends, whereupon a fuel-off interval begins;
- said secondary-delivery interval begins immediately after said primary-delivery interval ends;
- and
- said fuel-off interval continues throughout said secondary-delivery interval;
- a heat exchanger;
- signal-receiving means, coupling said thermostat and said heating means, for:
- initiating one of said fuel-on intervals, which begins when said signal-receiving means receives a FUEL=1 signal from said thermostat;
- terminating said fuel-on interval and initiating a fuel-off interval in which said furnace does not consume fuel, said fuel-off interval beginning when said signal-receiving means receives a FUEL=0 signal from said thermostat;
- initiating one of said delivery intervals, which begins when said signal-receiving means receives a DELY=1 signal from said thermostat;
- and
- terminating said delivery interval and initiating a nondelivery interval in which said furnace does not deliver heat to said space, said nondelivery interval beginning when said signal-receiving means receives a DELY=0 signal from said thermostat;
- said thermostat including:
- a timer providing timing signals;
- a temperature sensor having means for providing a space-temperature signal representative of said space temperature;
- means for providing a set-point-temperature signal representative of a set-point temperature;
- and
- means for providing said FUEL=O, FUEL=1, DELY=0, and DELY=1 signals;
- said thermostat further comprising:
- means for providing a maximum-on signal representative of a maximum fuel-on interval, where said maximum-on signal is provided by signal generating means for providing a signal representative of how long said heat exchanger can operate during a fuel-on interval in a linear mode before its mode of operation becomes nonlinear;
- burn-control means for causing a fuel-on interval to have a duration of no longer than said maximum fuel-on interval and for causing a fuel-off interval to have a duration of no less than said secondary-delivery interval;
- and
- further signal-generating means for providing a signal representative of said secondary-delivery interval, said further signal-generating means comprising means for providing a signal representative of how long it takes after a fuel-off interval begins before said heat exchanger falls to a temperature level such that said space temperature of said space no longer increases as a result of delivery of air from said heat exchanger.
23 more elements
A fuel-conserving thermostat for controlling operation of a heating system that consumes fuel during a fuel-on interval and heats a defined space, thereby increasing a space temperature of said space;
- said space being thermally conductive to an ambient, whereby a heat flux occurs from said space to said ambient;
- said heating system comprising:
- heating means for providing heat during said fuel-on interval;
- delivery means for delivering said heat to said space during a delivery interval, whereby a heat flux occurs from said heating means to said space during said delivery interval;
- a heat exchanger;
- signal-receiving means, coupling said thermostat and said heating means, for:
- initiating one of said fuel-on intervals, which begins when said signal-receiving means receives a FUEL=1 signal from said thermostat;
- terminating said fuel-on interval and initiating a fuel-off interval in which said furnace does not consume fuel, said fuel-off interval beginning said signal-receiving means receives a FUEL=0 when said signal-receiving means receives a FUEL=0 signal from said thermostat;
- initiating one of said delivery intervals, which begins when said signal-receiving means receives a DELY=1 signal from said thermostat;
- and
- terminating said delivery interval and initiating a nondelivery interval in which said furnace does not deliver heat to said space, said nondelivery interval beginning when said signal-receiving means receives a DELY=0 signal from said thermostat;
- said thermostat including:
- a timer providing timing signals;
- a temperature sensor having means for providing a space-temperature signal representative of said space temperature;
- means for providing a set-point-temperature signal representative of a set-point-temperature;
- and
- means for providing said FUEL=0, FUEL=1, DELY=0, and DELY=1 signals;
- said thermostat further comprising:
- means for providing a maximum-on signal representative of a maximum fuel-on interval, said maximum-on signal being provided by signal-generating means for providing a signal representative of how long said heat exchanger can operate during a fuel-on interval in a linear mode before its mode of operation becomes nonlinear, said signal-generating means comprising a probe means for measuring changes over time of a temperature representative of the temperature of the heat exchanger of the specific heating system installed at the location of the defined space;
- first burn-control means for causing a fuel-on interval having a duration of no longer than said maximum fuel-on interval;
- delivery-control means for causing heat to be delivered to said space during a delivery interval comprising said fuel-on interval and continuing after it ends until said heat exchanger falls to a temperature level such that said heat exchanger can operate in a linear mode during a next-following fuel-on interval;
- and
- second burn-control means for causing a nondelivery interval to follow said delivery interval for a duration at least as long as said heat exchanger takes to fall to said temperature level;
- and
- said temperature sensor having a deadband of from 1 to 4 degrees Fahrenheit.
22 more elements
A fuel-conserving thermostat for controlling operation of a heating system that consumes fuel during a fuel-on interval and heats a defined space, thereby increasing a space temperature of said space;
- said space being thermally conductive to an ambient, whereby a heat flux occurs from said space to said ambient;
- said heating system comprising:
- heating means for providing heat during said fuel-on interval;
- delivery means for delivering said heat to said space during a delivery interval, whereby a heat flux occurs from said heating means to said space during said delivery interval;
- a heat exchanger;
- signal-receiving means, coupling said thermostat and said heating means, for:
- initiating one of said fuel-on intervals, which begins when said signal-receiving means receives a FUEL=1 signal from said thermostat;
- terminating said fuel-on interval and initiating a fuel-off interval in which said furnace does not consume fuel, said fuel-off interval beginning said signal-receiving means receives a FUEL=0 when said signal-receiving means receives a FUEL=0 signal from said thermostat;
- initiating one of said delivery intervals, which begins when said signal-receiving means receives a DELY=1 signal from said thermostat;
- and
- terminating said delivery interval and initiating a nondelivery interval in which said furnace does not deliver heat to said space, said nondelivery interval beginning when said signal-receiving means receives a DELY=0 signal from said thermostat;
- said thermostat including:
- a timer providing timing signals;
- a temperature sensor having means for providing a space-temperature signal representative of said space temperature;
- means for providing a set-point-temperature signal representative of a set-point-temperature;
- and
- means for providing said FUEL=O, FUEL=1, DELY=0, and DELY=1 signals;
- said thermostat further comprising:
- means for providing a maximum-on signal representative of a maximum fuel-on interval, said maximum-on signal being provided by signal-generating means for providing a signal representative of how long said heat exchanger can operate during a fuel-on interval in a linear mode before its mode of operation becomes nonlinear, said signal-generating means comprising a probe means for measuring changes over time of a temperature representative of the temperature of the heat exchanger of the specific heating system installed at the location of the defined space;
- first burn-control means for causing a fuel-on interval having a duration of no longer than said maximum fuel-on interval;
- delivery-control means for causing heat to be delivered to said space during a delivery interval comprising said fuel-on interval and continuing after it ends until said heat exchanger falls to a temperature level such that said space temperature of said space no longer increases as a result of delivery of air from said heat exchanger;
- and
- second burn-control means for causing a nondelivery interval to follow said delivery interval for a duration at least as long as said heat exchanger takes to fall to said temperature level.
20 more elements
A method for conserving energy utilization in a heating system for heating a defined space and thereby increasing a space temperature of said space;
- said space being thermally conductive to an ambient, whereby a heat flux occurs from said space to said ambient;
- said heating system
- consuming fuel, during a fuel-on interval, to provide heat;
- delivering said heat, during a delivery interval, to said space;
- having a heat exchanger;
- having signal-receiving means coupled to a thermostat, for:
- initiating one of said fuel-on intervals, which begins when said means receives a FUEL=1 signal from said thermostat;
- terminating said fuel-on interval and initiating a fuel-off interval in which said heating system does not consume fuel, said fuel-off interval beginning when said signal-receiving means receives a FUEL=0 signal from said thermostat;
- initiating one of said delivery intervals, which begins when said signal-receiving means receives a DELY=1 signal;
- and
- terminating said delivery interval and initiating a nondelivery interval, during which said heating system does not deliver heat to said space, said nondelivery interval beginning when said signal-receiving means receives a DELY=0 signal;
- said thermostat including a temperature sensor for providing temperature measurements to said thermostat, said temperature sensor having coupled thereto means for predetermining a deadband for said temperature sensor
- said method comprising:
- (1) utilizing said means for predetermining a deadband for said temperature sensor to set said deadband at from 1 to 4 degrees Fahrenheit;
- (2) providing said thermostat with a signal maximum-on representative of a maximum fuel-on interval, where said maximum fuel-on interval is how long said heat exchanger can operate during a fuel-on interval in a linear mode before its mode of operation becomes nonlinear;
- (3) sending from said thermostat to said signal-receiving means FUEL=1 signals of duration no longer than said maximum fuel-on interval;
- (4) when one of said FUEL=1 signals reaches a duration of said maximum fuel-on interval, sending a FUEL=0 signal from said thermostat to said signal-receiving means;
- and
- (5) sending from said thermostat to said signal-receiving means DELY=1 signals while said thermostat sends said FUEL=1 signals.
16 more elements
A method for conserving energy utilization in a heating system for heating a defined space and thereby increasing a space temperature of said space;
- said space being thermally conductive to an ambient, whereby a heat flux occurs from said space to said ambient;
- said heating system
- consuming fuel, during a fuel-on interval, to provide heat;
- delivering said heat, during a delivery interval, to said space;
- having a heat exchanger;
- having signal-receiving means coupled to a thermostat, for:
- initiating one of said fuel-on intervals, which begins when said means receives a FUEL=1 signal from said thermostat;
- terminating said fuel-on interval and initiating a fuel-off interval in which said heating system does not consume fuel, said fuel-off interval beginning when said signal-receiving means receives a FUEL=0 signal from said thermostat;
- initiating one of said delivery intervals, which begins when said signal-receiving means receives a DELY=1 signal;
- and
- terminating said delivery interval and initiating a nondelivery interval, during which said heating system does not deliver heat to said space, said nondelivery interval beginning when said signal-receiving means receives a DELY=0 signal;
- said thermostat including a temperature sensor for providing temperature measurements to said thermostat
- said method comprising:
- (1) providing said thermostat with a signal maximum-on representative of a maximum fuel-on interval, where said maximum fuel-on interval is how long said heat exchanger can operate during a fuel-on interval in a linear mode before its mode of operation becomes nonlinear;
- (2) sending from said thermostat to said signal-receiving means FUEL=1 signals of duration no longer than said maximum fuel-on interval;
- (3) when one of said FUEL=1 signals reaches a duration of said maximum fuel-on interval, sending a FUEL=0 signal from said thermostat to said signal-receiving means;
- (4) sending from said thermostat to said signal-receiving means DELY=1 signals while said thermostat sends said FUEL=1 signals;
- and
- (5) continuing to send from said thermostat to said signal-receiving means DELY=1 signals until said heat exchanger falls to a temperature level such that said space temperature of said space no longer increases as a result of delivery of air from said heat exchanger.
16 more elements
A method for decreasing or limiting peak load usage of fuel in a plurality of buildings, said method comprising installing in each of said buildings a thermostat for controlling a heating system of said building, wherein said thermostat:
- comprises means for limiting a fuel-on interval of said heating system to no longer than a predetermined maximum fuel-on interval, where said maximum fuel-on interval is how long said heating system's heat exchanger can operate in a linear mode during a fuel-on interval before operating in a nonlinear mode;
- and
- has a deadband of 1 to 4 degrees Fahrenheit.
A method for decreasing or limiting peak load usage of fuel in a plurality of buildings, said method comprising installing in each of said buildings a thermostat for controlling a heating system of said building, wherein said thermostat comprises:
- means for limiting a fuel-on interval of said heating system to no longer than a predetermined maximum fuel-on interval, where said maximum fuel-on interval is how long said heating system's heat exchanger can operate in a linear mode during a fuel-on interval before operating in a nonlinear mode;
- and
- means for initiating a fuel-off interval of said heating system, said fuel-off interval continuing for at least a predetermined secondary-delivery interval, where said secondary-delivery interval is how long it takes after said fuel-off interval begins before said space temperature of said space is no longer increased by a further delivery of air.
Dependencies are inferred from the claim text.