Abstract: A device is configured to operate a Heating, Ventilation, and Air Conditioning (HVAC) system. The device is further configured to determine that the speed of a combustion air inducer exceeds a speed threshold value. The device is further configured to receive an audio signal from a microphone while operating the HVAC system and to determine an audio signature for the combustion air inducer is not present within the audio signal. The device is further configured to determine whether an audio signature for the integrated furnace controller is present within the audio signal. The device is further configured to determine a fault type based on the determination of whether the audio signature for the integrated furnace controller is present within the audio signal, to identify a component identifier for a component of the HVAC system that is associated with fault type, and to output a recommendation identifying the component identifier.

Abstract: A method of monitoring a heating, ventilation, and air conditioning (HVAC) system for refrigerant leak. The method includes monitoring, by a controller, operation of the HVAC system and determining, using a plurality of leak detectors, whether refrigerant within the HVAC system is leaking. Responsive to a positive determination in the determining step, receiving, by the controller, a refrigerant leak warning signal and modifying, by the controller, operation of the HVAC system to prevent the refrigerant from entering an enclosed space.

Abstract: 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.

Abstract: A heating, ventilation, and air conditioning (HVAC) control device is configured to record a plurality of actual occupancy statuses, to determine a plurality of corresponding predicted occupancy statuses, and to compare the plurality of predicted occupancy statuses to the plurality of actual occupancy statuses. The device is further configured to identify conflicting occupancy statuses based on the comparison. A conflicting occupancy status indicates a difference between an actual occupancy status and a corresponding predicted occupancy status. The device is further configured to identify timestamps corresponding with the conflicting occupancy statuses, to identify historical occupancy statuses corresponding with the identified timestamps, and to update the conflicting occupancy statuses in the predicted occupancy schedule with the historical occupancy statuses.

Abstract: A heating, ventilation, and air conditioning (HVAC) control device configured to generate the machine learning model using the first set of weights and the second set of weights. The machine learning model is configured to output a probability that a user is present at the space based on an input that identifies a day of the week and a time of a day. The device is further configured to determine a probability that a user is present at the space for a predicted occupancy schedule using the machine learning model, to determine an occupancy status based on a determined probability that a user is present at the space, and to set a predicted occupancy status in the predicted occupancy schedule based on a determined occupancy status for each time entry. The device is further configured to output the predicted occupancy schedule.

Abstract: A device is configured to operate a Heating, Ventilation, and Air Conditioning (HVAC) system. The device is further configured to determine that the amount of time to close a pressure switch exceeds a time threshold value. The device is further configured to receive an audio signal from a microphone while operating the HVAC system, to identify an audio signature for the combustion air inducer, and to determine the audio signature for the combustion air inducer is present within the audio signal. The device is further configured to determine a fault type based on the determination that the audio signature for the combustion air inducer is present within the audio signal, to identify a component identifier for a component of the HVAC system that is associated with fault type, and to output a recommendation identifying the component identifier.

Abstract: A heating, ventilation, and air conditioning (HVAC) control device configured to collect event data from the one or more devices and to populate time entries in an occupancy history log with the event data. The event data includes a timestamp indicating a time when an event occurred, a set point temperature value for the HVAC system, and an occupancy status indicating whether a space is occupied. The device is further configured to identify blank time entries in the occupancy history log and to populate the blank time entries by forward filling the occupancy history log using event data from another time entry in the occupancy history log. The device is further configured to output the populated occupancy history log.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A device is configured to operate a Heating, Ventilation, and Air Conditioning (HVAC) system. The device is further configured to determine that the speed of a combustion air inducer exceeds a speed threshold value. The device is further configured to receive an audio signal from a microphone while operating the HVAC system and to determine an audio signature for the combustion air inducer is not present within the audio signal. The device is further configured to determine whether an audio signature for the integrated furnace controller is present within the audio signal. The device is further configured to determine a fault type based on the determination of whether the audio signature for the integrated furnace controller is present within the audio signal, to identify a component identifier for a component of the HVAC system that is associated with fault type, and to output a recommendation identifying the component identifier.

Abstract: A device is configured to operate a Heating, Ventilation, and Air Conditioning (HVAC) system. The device is further configured to determine that the amount of time to close a pressure switch exceeds a time threshold value. The device is further configured to receive an audio signal from a microphone while operating the HVAC system, to identify an audio signature for the combustion air inducer, and to determine the audio signature for the combustion air inducer is present within the audio signal. The device is further configured to determine a fault type based on the determination that the audio signature for the combustion air inducer is present within the audio signal, to identify a component identifier for a component of the HVAC system that is associated with fault type, and to output a recommendation identifying the component identifier.

Abstract: A device is configured to operate a Heating, Ventilation, and Air Conditioning (HVAC) system. The device is further configured to determine that the amount of time to close a pressure switch exceeds a time threshold value. The device is further configured to receive an audio signal from a microphone while operating the HVAC system and to determine that an audio signature for a combustion air inducer is not present within the audio signal. The device is further configured to determine whether an audio signature for an integrated furnace controller is present within the audio signal. The device is further configured to determine a fault type based on the determination of whether the audio signature for the integrated furnace controller is present within the audio signal, to identify a component identifier for a component of the HVAC system associated with fault type, and to output a recommendation identifying the component identifier.

Abstract: A device is configured to operate a Heating, Ventilation, and Air Conditioning (HVAC) system. The device is further configured to determine that the amount of time to ignite a burner in a burner assembly has exceeded a time threshold value and that a flame was not detected by a flame sensor. The device is further configured to receive an audio signal from a microphone while operating the HVAC system, to identify an audio signature for the flame, and to determine whether the audio signature for the flame is present within the first audio signal. The device is further configured to determine a fault type based on the determination of whether the audio signature for the flame is present within the audio signal, to identify a component identifier for a component of the HVAC system that is associated with fault type, and to output a recommendation identifying the component identifier.

Abstract: A device is configured to operate a Heating, Ventilation, and Air Conditioning (HVAC) system. The device is further configured to determine that the speed of a combustion air inducer has exceeded a speed threshold value. The device is further configured to receive an audio signal from a microphone while operating the HVAC system, to identify an audio signature for the combustion air inducer from an audio signature library, and to determine the audio signature for the combustion air inducer is present within the audio signal. The device is further configured to determine a fault type based on the determination that the audio signature for the combustion air inducer is present within the audio signal, to identify a component identifier for a component of the HVAC system that is associated with fault type, and to output a recommendation identifying the component identifier.

Abstract: 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.

Abstract: A method of monitoring a HVAC system to detect erroneous sensor installation. The method includes determining whether a circulation fan has been operational for a first predetermined time interval. If the circulation fan has been operational for the first predetermined time interval, determining whether a cooling demand is present. If the cooling demand is present, determining whether the HVAC system has been conditioning air for the first predetermined time interval responsive to the cooling demand. If the HVAC system has been conditioning the air for the first predetermined time interval, determining whether a difference between an indoor air temperature value corresponding to an enclosed space and an air temperature value from a discharge air temperature (DAT) sensor is greater than a predetermined temperature value.

Abstract: A heating, ventilation, and air conditioning (HVAC) control device configured to receive a user input for controlling an HVAC system, to determine whether the user input indicates an energy saving occupancy setting, and to identify a first plurality of time entries that are associated with a confidence level for a predicted occupancy status that is less than a predetermined threshold value in the predicted occupancy schedule. The device is further configured to modify the predicted occupancy schedule by setting the first plurality of time entries to an away status when the user input indicates an aggressive energy saving occupancy setting. The device is further configured to modify the predicted occupancy schedule by setting the second plurality of time entries to a present status when the user input indicates a conservative energy saving occupancy setting. The device is further configured to output the modified predicted occupancy schedule.

Abstract: A heating, ventilation, and air conditioning (HVAC) control device configured to receive a user input for controlling an HVAC system, to determine whether the user input indicates an energy saving occupancy setting, and to identify a first plurality of time entries that are associated with a confidence level for a predicted occupancy status that is less than a predetermined threshold value in the predicted occupancy schedule. The device is further configured to modify the predicted occupancy schedule by setting the first plurality of time entries to an away status when the user input indicates an aggressive energy saving occupancy setting. The device is further configured to modify the predicted occupancy schedule by setting the second plurality of time entries to a present status when the user input indicates a conservative energy saving occupancy setting. The device is further configured to output the modified predicted occupancy schedule.

Abstract: A heating, ventilation, and air conditioning (HVAC) control device configured to receive a user input for controlling an HVAC system, to determine whether the user input indicates an energy saving occupancy setting, and to identify a first plurality of time entries that are associated with a confidence level for a predicted occupancy status that is less than a predetermined threshold value in the predicted occupancy schedule. The device is further configured to modify the predicted occupancy schedule by setting the first plurality of time entries to an away status when the user input indicates an aggressive energy saving occupancy setting. The device is further configured to modify the predicted occupancy schedule by setting the second plurality of time entries to a present status when the user input indicates a conservative energy saving occupancy setting. The device is further configured to output the modified predicted occupancy schedule.