Abstract: A method of operating a HVAC system is provided. The method includes transferring heat between airflow and a heating element in the duct system. The heating element is configured to receive a fuel and ignite the fuel to heat the heating element. The method includes measuring a change in at least one gas property value of the airflow in the duct system using a leak detection sensor, where the change in the at least one gas property value is indicative of a gas leaked into the duct system. The method includes determining a concentration of the leaked gas based at least in part upon the change in the at least one gas property value and determining that the concentration as measured by the leak detection sensor has a negative value, where the negative value is indicative of the leaked gas comprising fuel.

Abstract: A heating, ventilation and air conditioning (HVAC) controller, a method of detecting multiplexed input signals and an HVAC system employing the controller or the method. In one embodiment, the HVAC controller includes: (1) a signal conditioner configured to convert received alternating current (AC) input signals into corresponding square wave signals of a digital logic voltage, (2) a multiplexer coupled to the signal conditioner and configured to select one of the square wave signals and (3) a sample analyzer coupled to the multiplexer and configured to evaluate multiple samples of the selected one of the square wave signals to derive a binary state.

Abstract: A heating, ventilation and air conditioning (HVAC) controller, a method of detecting multiplexed input signals and an HVAC system employing the controller or the method. In one embodiment, the HVAC controller includes: (1) a signal conditioner configured to convert received alternating current (AC) input signals into corresponding square wave signals of a digital logic voltage, (2) a multiplexer coupled to the signal conditioner and configured to select one of the square wave signals and (3) a sample analyzer coupled to the multiplexer and configured to evaluate multiple samples of the selected one of the square wave signals to derive a binary state.

Abstract: A heating, ventilation and air conditioning (HVAC) controller, a method of detecting multiplexed input signals and an HVAC system employing the controller or the method. In one embodiment, the HVAC controller includes: (1) a signal conditioner configured to convert received alternating current (AC) input signals into corresponding square wave signals of a digital logic voltage, (2) a multiplexer coupled to the signal conditioner and configured to select one of the square wave signals and (3) a sample analyzer coupled to the multiplexer and configured to evaluate multiple samples of the selected one of the square wave signals to derive a binary state.

Abstract: A tray for an HVAC controller includes a tray base, a first mounting tab secured to the tray base and configured to interlock with a corresponding mount of a cabinet of an indoor unit of an HVAC system, a mounting bracket secured to the tray base and comprising an aperture for receiving a mounting screw therethrough, a drip wall that extends up from the tray base, and a cover extending up from the tray base that includes a wall and a top plate. The cover is positioned to protect a component of the HVAC controller from impact when the HVAC controller is installed in the tray.

Abstract: Provided herein are embodiments of, a multistage gas furnace, a controller therefor and a computer-usable medium having non-transitory computer readable instructions stored thereon for execution by a processor to perform a method for operating a gas furnace. In one embodiment, the gas furnace includes: (1) a burner, (2) a circulation fan and (3) a furnace controller. The furnace controller having: (3A) an interface configured to receive heating calls and a blower control signal, the blower control signal corresponding to an operating speed of the circulation fan and (3B) a processor configured to respond to the heating calls and the blower control signal by setting and adjusting a gas input rate for the burner that is based on the blower control signal and that corresponds to a discharge air temperature determined by a dedicated discharge air sensor associated with the furnace.

Abstract: An HVAC controller includes (1) an interface coupled to an air quality sensor proximate to the premises and coupled to a data source external to the HVAC system, the interface configured to receive environmental data from both the air quality sensor and the external data source and (2) a processor configured to automatically operate a demand unit of the HVAC system based on the environmental data.

Abstract: The disclosure provides a proportional control signal circuit (PCSC), an HVAC controller employing the same and an HVAC system including the HVAC controller. In one embodiment, the PCSC includes: (1) a signal input configured to receive a pulse width modulated signal, (2) a control input configured to receive an integration signal, (3) a signal output and (4) control circuitry, coupled to the signal input, the control input and the signal output, configured to provide either the pulse width modulated signal or a DC signal to the signal output based on the integration signal.

Abstract: A heating, ventilation and air conditioning (HVAC) controller, a method of receiving signals from a keypad and an HVAC system incorporating the controller or the method. In one embodiment, the HVAC controller includes: (1) a keypad having at least first and second banks, (2) a reference signal source configured to generate a time-varying untransformed reference signal and provide the untransformed reference signal to the first bank, (3) transformation circuitry configured to transform the untransformed reference signal into a transformed reference signal and provide the transformed reference signal to the second bank and (4) a processor having interrupt pins coupled to corresponding keys of both the first and second banks and a further interrupt pin coupled to receive one of the untransformed and transformed reference signal.

Abstract: A heating, ventilation and air conditioning (HVAC) controller, a method of detecting multiplexed input signals and an HVAC system employing the controller or the method. In one embodiment, the HVAC controller includes: (1) a signal conditioner configured to convert received alternating current (AC) input signals into corresponding square wave signals of a digital logic voltage, (2) a multiplexer coupled to the signal conditioner and configured to select one of the square wave signals and (3) a sample analyzer coupled to the multiplexer and configured to evaluate multiple samples of the selected one of the square wave signals to derive a binary state.

Abstract: A heating, ventilation and air conditioning (HVAC) controller, a method of detecting multiplexed input signals and an HVAC system employing the controller or the method. In one embodiment, the HVAC controller includes: (1) a signal conditioner configured to convert received alternating current (AC) input signals into corresponding square wave signals of a digital logic voltage, (2) a multiplexer coupled to the signal conditioner and configured to select one of the square wave signals and (3) a sample analyzer coupled to the multiplexer and configured to evaluate multiple samples of the selected one of the square wave signals to derive a binary state.

Abstract: An HVAC system, comprising a plurality of sensors, a tandem compressor comprising a first compressor and a second compressor, and a controller communicatively coupled to the plurality of sensors and the tandem compressor. The controller may determine a first interruption of power to the tandem compressor and identify a sensor corresponding to the first interruption of power. The controller is further operable to determine that the first interruption of power was caused at least in part by the refrigerant associated with the first compressor exceeding a tolerance condition. The controller may also reconfigure the tandem compressor, wherein on or off settings of the first compressor and the second compressor are determined based on a required load operation of the tandem compressor and the determination that the first interruption of power was caused at least in part by the refrigerant associated with the first compressor exceeding the tolerance condition.

Abstract: The disclosure provides a proportional control signal circuit (PCSC), an HVAC controller employing the same and an HVAC system including the HVAC controller. In one embodiment, the PCSC includes: (1) a signal input configured to receive a pulse width modulated signal, (2) a control input configured to receive an integration signal, (3) a signal output and (4) control circuitry, coupled to the signal input, the control input and the signal output, configured to provide either the pulse width modulated signal or a DC signal to the signal output based on the integration signal.

Abstract: A heating, ventilation and air conditioning (HVAC) controller, a method of receiving signals from a keypad and an HVAC system incorporating the controller or the method. In one embodiment, the HVAC controller includes: (1) a keypad having at least first and second banks, (2) a reference signal source configured to generate a time-varying untransformed reference signal and provide the untransformed reference signal to the first bank, (3) transformation circuitry configured to transform the untransformed reference signal into a transformed reference signal and provide the transformed reference signal to the second bank and (4) a processor having interrupt pins coupled to corresponding keys of both the first and second banks and a further interrupt pin coupled to receive one of the untransformed and transformed reference signal.

Abstract: The disclosure provides a proportional control signal circuit (PCSC), an HVAC controller employing the same and an HVAC system including the HVAC controller. In one embodiment, the PCSC includes: (1) a signal input configured to receive a pulse width modulated signal, (2) a control input configured to receive an integration signal, (3) a signal output and (4) control circuitry, coupled to the signal input, the control input and the signal output, configured to provide either the pulse width modulated signal or a DC signal to the signal output based on the integration signal.

Abstract: A heating, ventilation and air conditioning (HVAC) controller, a method of receiving signals from a keypad and an HVAC system incorporating the controller or the method. In one embodiment, the HVAC controller includes: (1) a keypad having at least first and second banks, (2) a reference signal source configured to generate a time-varying untransformed reference signal and provide the untransformed reference signal to the first bank, (3) transformation circuitry configured to transform the untransformed reference signal into a transformed reference signal and provide the transformed reference signal to the second bank and (4) a processor having interrupt pins coupled to corresponding keys of both the first and second banks and a further interrupt pin coupled to receive one of the untransformed and transformed reference signal.

Abstract: Provided herein are embodiments of, a multistage gas furnace, a controller therefor and a computer-usable medium having non-transitory computer readable instructions stored thereon for execution by a processor to perform a method for operating a gas furnace. In one embodiment, the gas furnace includes: (1) a burner, (2) a circulation fan and (3) a furnace controller. The furnace controller having: (3A) an interface configured to receive heating calls and a blower control signal, the blower control signal corresponding to an operating speed of the circulation fan and (3B) a processor configured to respond to the heating calls and the blower control signal by setting and adjusting a gas input rate for the burner that is based on the blower control signal and that corresponds to a discharge air temperature determined by a dedicated discharge air sensor associated with the furnace.

Abstract: Provided herein are embodiments of a multistage gas furnace, a controller therefor and a computer-usable medium having non-transitory computer readable instructions stored thereon for execution by a processor to perform a method for operating a gas furnace. In one embodiment, the gas furnace includes: (1) a burner, (2) a circulation fan and (3) a furnace controller. The furnace controller having: (3A) an interface configured to receive heating calls and a blower control signal, the blower control signal corresponding to an operating speed of the circulation fan and (3B) a processor configured to respond to the heating calls and the blower control signal by setting and adjusting a gas input rate for the burner that is based on the blower control signal and that corresponds to a discharge air temperature determined by a dedicated discharge air sensor associated with the furnace.

Abstract: The disclosure provides, in one aspect, an integrated controller for a HVAC system is disclosed. In one embodiment, the integrated controller includes: (1) an interface coupled to an auxiliary controller of the HVAC system and configured to communicate therewith, the auxiliary controller having an auxiliary non-volatile memory, (2) a processor, coupled to the interface and configured to direct the operation of the HVAC system, and (3) a main non-volatile memory coupled to the processor and configured to receive a copy of main controller application information associated with the main system controller via the interface and store the main controller application information, the processor further configured to automatically send a copy of the main controller application information during manufacturing of the HVAC system to the auxiliary controller of the HVAC system to store as back-up data on the auxiliary non-volatile memory of the auxiliary controller.

Abstract: The disclosure provides, in one aspect, a method of starting a HVAC system is disclosed. In one embodiment, the method includes: (1) receiving an initiation signal at a main system controller of the HVAC system, (2) determining if main controller application information associated with the main system controller is stored thereon, (3) querying an auxiliary controller of the HVAC system when determining the main controller application information is not stored on the main system controller, (4) sending the main controller application information to the main system controller from the auxiliary controller when the auxiliary controller includes the main controller application information, and (5) initiating the HVAC system based on the initiation signal and employing the main controller application information sent to the main system controller from the auxiliary controller.