Lennox Industries Inc.

Pete Hrejsa

Eric Berg

Yi Qu

Rakesh Goel

Rohini Brahme

Chao Xia

Henry Greist

Sanjeev Hingorani

Dhishan Kande

Elena Smirnova

Emile Abi-Habib

Takeshi Sakai

An HVAC system includes one or more air quality sensors, each configured to measure an air quality and a thermostat communicatively coupled to the one or more air quality sensors. The thermostat receives indoor air quality measurements from the one or more air quality sensors. An indoor air quality score is determined based at least in part on the received indoor air quality measurements. The thermostat determines, based at least in part on the indoor air quality score, a mitigation action, wherein the mitigation action comprises one or more actions selected from the group of: (i) a filtering action comprising filtering air provided to the space using an air purification subsystem, and (ii) a ventilation action comprising ventilating the space using a ventilation subsystem. The mitigation action is executed, or implemented, by adjusting one or more components of the HVAC system.

HVAC system with indoor air quality monitoring and mitigation

A system includes multiple HVAC systems. After receiving a demand request, a multiple-system controller a first anticipated power consumption associated with operating a first HVAC system at a first temperature setpoint during a future period of time of the demand response request and a second anticipated power consumption associated with operating a second HVAC system at a second temperature setpoint during the future period of time. Based at least in part on the first and the second anticipated power consumptions, a staging schedule is determined that indicates when to operate the first and second HVAC systems.

Automatic staging of multiple HVAC systems during a peak demand response

A system includes multiple HVAC systems. After receiving a demand request, a multiple-system controller determines a first anticipated power consumption associated with operating a first HVAC system at a first temperature setpoint during a future period of time of the demand response request and a second anticipated power consumption associated with operating a second HVAC system at a second temperature setpoint during the future period of time. Based at least in part on the first and the second anticipated power consumptions, a staging schedule is determined that indicates when to operate the first and second HVAC systems.

A defrost method for a heat pump system includes running the heat pump system in a heating mode to provide heat to an enclosed space and determining if an outdoor temperature is less than an outdoor threshold temperature. Responsive to a determination that the outdoor temperature is below the outdoor threshold temperature, determining if a calibration state has been previously run. Responsive to a determination that the calibration state has not been previously run, running the heat pump system in the calibration state. Responsive to a determination that the calibration state has been previously run, determining if a temperature difference between a temperature of an evaporator coil of the heat pump system and the outdoor temperature exceeds a temperature threshold value. Responsive to a determination that the temperature difference between the evaporator coil and the outdoor temperature is greater than the temperature threshold value, running the heat pump system in a defrost state.

Demand defrost with frost accumulation failsafe

In various implementations, a request for operation of an air conditioner may be received. The air conditioner may include a cooling mode and/or a dehumidifying mode. In some implementations, a compressor speed for a compressor of the air conditioner may be determined, and which mode(s) of the air conditioner to allow may be determined based at least partially on the determined compressor speed.

Controlling air conditioner modes

One aspect presents a controller that comprises a control board, a microprocessor located on and electrically coupled to the control board, and a memory coupled to the microprocessor and located on and electrically coupled to the control board. The controller is configured to receive an operating parameter signal and recalculate a first maximum heating % demand to a second maximum heating % demand that is greater than the first maximum heating % demand, when a value of the operating parameter signal exceeds a predetermined value, and operate the HP system based on the second maximum heating % demand.

Heat pump system having a maximum percent demand re-calculation algorithm controller

In various implementations, defrost operations may be managed. A change in the temperature of a heat exchanger may be determined. A determination whether to allow a defrost operation may be at least partially based on the determined change in the temperature of the heat exchanger.

Defrost operation management

One aspect presents an controller that comprises a control board, a microprocessor located on and electrically coupled to the control board, and a memory coupled to the microprocessor and located on and electrically coupled to the control board. The controller is configured to receive a trip signal from a refrigerant high pressure sensor and set a maximum heating % demand of the heat pump system based on the trip signal, recalculate a heating % demand based on at least one of the recalculated heating % demand or the maximum heating % demand.

Heat pump system having a pressure trip sensor recalculation algorithm controller

A method of operating a heat pump system is provided, the heat pump system having at least a controller and configured to operate at least two defrost cycles. The method comprises receiving, at the controller, weather data for a defined geographic area proximate to an installed location of the heat pump system; and selecting, based on said weather data, one of the at least two defrost cycles.

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Frisco, TX, United States of America

Pete Hrejsa