Lennox Industries Inc.

Eric Berg

Rakesh Goel

Umesh Gokhale

Payam Delgoshaei

Pete Hrejsa

Mark W Olsen

Jon Douglas

Wenqian Liu

Carl Travis Crawford

Austin Clay Styer

Eric M Perez

Robert B Uselton

Glenn Will Kowald

Sridhar Venkatesh

Yi Qu

Ian Burmania

Glenn William Kowald

Jeff Mangum

Ajay Iyengar

Srini Natarajan

Janathkumar Manohararaj

Peter Hrejsa

Jeffrey Fontenault

A method for heating, ventilation, and air conditioning (HVAC) system diagnostics includes sending a first instruction to a thermostat to shut down an HVAC system. A user is instructed to minimize background noise. A second instruction is sent to the thermostat to turn on the HVAC system. A third instruction is sent to the thermostat to set a temperature setpoint below or above a value of a room temperature. Outdoor unit sound data is captured for a second time period. The baseline sound data is subtracted from the outdoor unit sound data to determine normalized outdoor unit sound data. Expected sound signatures of the outdoor unit are identified. The normalized outdoor unit sound data is compared to the expected sound signatures. In response to determining that an expected sound signature for a compressor is missing from the normalized outdoor unit sound data, it is determined that the compressor has failed.

Diagnostics of outdoor unit of HVAC system based on sound signatures

A device is configured to operate a Heating, Ventilation, and Air Conditioning (HVAC) system. The device is further configured to receive a temperature value and determine a load demand value based on the temperature value. The device is further configured to determine the load demand value is greater than the load capacity value for the HVAC system and, in response, identify a first setting from among a first plurality of settings for the HVAC system. By default, access to the first plurality of setting for the HVAC system is restricted for a user. The device is further configured to receive a response approving permission to operate the HVAC system using the first setting to the user and send a trigger signal to an HVAC controller to operate the one or more components of the HVAC system using the first setting.

Dynamic temperature control for a heating, ventilation, and air conditioning system

An HVAC system includes a high-pressure subsystem and a low-pressure subsystem. After determining that refrigerant leak diagnostics should be performed, a controllable valve is closed between a condenser and compressor of the HVAC system. The compressor then operates until a predetermined input refrigerant pressure is reached. After the predetermined input refrigerant pressure is reached, operation of the compressor is stopped. After stopping operation of the compressor and waiting at least a predetermined wait time, the pressure in the low-pressure subsystem of the HVAC system is monitored. A rate of change of the pressure in the low-pressure subsystem is determined. If the rate of change is negative and a magnitude of the rate of change is greater than a threshold value, a leak location is determined to be in the low-pressure subsystem.

HVAC system leak detection

An HVAC system includes an indoor heat-exchange coil disposed between a supply air duct and a return air duct. A damper is disposed in a re-circulation duct and is moveable between an open position and a closed position. A controller is configured to determine if the HVAC system is operating in a heating mode or an air-conditioning mode. Responsive to a determination that the HVAC system is operating in the air-conditioning mode, the controller is configured to determine if the variable-speed indoor circulation fan is operating at a minimum speed and if the relative humidity measured by the humidity sensor is above a pre-determined threshold. Responsive to a determination that the variable-speed indoor circulation fan is operating at the minimum speed and the relative humidity of the enclosed space is above the pre-determined threshold, the controller signals the damper to move to the open position.

Method and system for utilizing a bypass humidifier for dehumidification during cooling

A method of minimizing components of a heating, ventilation, and air conditioning (HVAC) system from malfunctioning, the method includes measuring, by an accelerometer associated with at least one component of the HVAC system, vibration of the at least one component and receiving, by a controller, actual vibration data reflective of the measured vibration. The method further includes determining, using the controller, whether the actual vibration data is greater than pre-defined acceptable baseline vibration data by more than a pre-defined acceptable amount and responsive to a positive determination in the determining step, adding, by the controller, as a deadband frequency, an operational frequency of the at least one component corresponding to the actual vibration data.

Method and apparatus for preventing component malfunction using accelerometers

A method of mitigating liquid-refrigerant migration includes comparing a requested compressor speed of a variable-speed compressor to a pre-defined threshold and, responsive to a determination that the requested compressor speed is greater than the pre-defined threshold, operating the variable-speed compressor at a first compressor speed that is less than the requested compressor speed.

Method and system for the heat-pump control to reduce liquid refrigerant migration

An HVAC system includes a heating element, a discharge air temperature sensor, and a return air temperature sensor. A controller of the HVAC system determines that the HVAC system has been operating in the heating mode for at least a predefined amount of time. The controller receives measurements of the discharge air temperature and the return air temperature. A temperature rise value is determined using the discharge air temperature and return air temperature. If the temperature rise value is less than a predefined minimum threshold value, the controller determines that a first fault of the HVAC system is detected and provides a corresponding alert. If the temperature rise value is greater than a predefined maximum threshold value, the controller determines that a second fault of the HVAC system is detected and provides a corresponding alert.

HVAC system prognostics and diagnostics based on temperature rise or drop

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

A device configured to operate a Heating, Ventilation, and Air Conditioning (HVAC) system and to receive an audio signal from a microphone while operating HVAC system. The device is further configured to generate a representation of the audio signal, to compare one or more audio signatures to the representation of the audio signal, and to determine that an audio signature from among the one or more audio signatures is not present within the representation of the audio signal. The device is further configured to determine a fault type that is associated with the audio signature that is not present within the representation of the audio signal, to identify a component identifier for a component of the HVAC system that is associated with fault type, and to output the component identifier.

Sound-based HVAC system, method and device for diagnostics analysis

An apparatus includes a high side heat exchanger, a second heat exchanger, a load, a variable speed compressor, and a three-way valve. The high side heat exchanger removes heat from a refrigerant. The second heat exchanger removes heat from the refrigerant. The load uses the refrigerant to remove heat from a space proximate the load. The variable speed compressor compresses the refrigerant from the load and directs the compressed refrigerant to the high side heat exchanger. The three-way valve, when operating in a first mode, directs the refrigerant from the high side heat exchanger to the load and when operating in a second mode, directs the refrigerant from the high side heat exchanger to the second heat exchanger.

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The Colony, TX, United States of America

Eric Berg