Diagnostics of outdoor unit of HVAC system based on sound signatures

Patent metadata

Field	Value
Publication number	US-12492835-B2
Application number	US-202318299482-A
Country	US
Kind code	B2
Filing date	Apr 12, 2023
Priority date	Apr 12, 2023
Publication date	Dec 9, 2025
Grant date	Dec 9, 2025

Abstract

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.

First claim

The invention claimed is:

1 . A system comprising:
a thermostat communicatively coupled to a heating, ventilation, and air conditioning (HVAC) system; a user device communicatively coupled to the thermostat, wherein the user device comprises a first processor configured to:
send a first instruction to the thermostat to shut down the HVAC system;
instruct a user to minimize background noise;
instruct the user to go to an outdoor unit of the HVAC system;
instruct the user to capture an image of a nameplate of the outdoor unit;
analyze the image to determine a distance of the user from the outdoor unit;
compare the distance to a distance range;
in response to determining that the distance is within the distance range, capture baseline sound data for a first time period;
send a second instruction to the thermostat to turn on the HVAC system;
determine a value of a room temperature;
send a third instruction to the thermostat to set a temperature setpoint below or above the value of the room temperature;
capture first outdoor unit sound data for a second time period; and
send the first outdoor unit sound data and the baseline sound data to a computing system; and
the computing system communicatively coupled to the user device, wherein the computing system comprises a second processor configured to:
subtract the baseline sound data from the first outdoor unit sound data to determine first normalized outdoor unit sound data;
analyze the first normalized outdoor unit sound data to determine first sound signatures;
identify expected first sound signatures of the outdoor unit;
compare the first normalized outdoor unit sound data to the expected first sound signatures;
in response to determining that an expected sound signature for a compressor is missing from the first normalized outdoor unit sound data, determine that the compressor has failed; and
send a first notification to the user device that the compressor has failed.

2 . The system of claim 1 , wherein the second processor is further configured to:
in response to determining that the expected sound signature for the compressor is not missing from the first normalized outdoor unit sound data:
in response to determining that the expected sound signature for the compressor is different from a respective sound signature of the compressor determined from the first normalized outdoor unit sound data, determine that the compressor is malfunctioning; and
send a second notification to the user device that compressor is malfunctioning.

3 . The system of claim 2 , wherein the second processor is further configured to:
in response to determining that the expected sound signature for the compressor is not different from the respective sound signature of the compressor determined from the first normalized outdoor unit sound data:
in response to determining that an expected sound signature for an outdoor fan is missing from the first normalized outdoor unit sound data, determine that the outdoor fan has failed; and
send a third notification to the user device that the outdoor fan has failed.

4 . The system of claim 3 , wherein the second processor is further configured to:
in response to determining that the expected sound signature for the outdoor fan is not missing from the first normalized outdoor unit sound data:
in response to determining that the expected sound signature for the outdoor fan is different from a respective sound signature of the outdoor fan determined from the first normalized outdoor unit sound data, determine that the outdoor fan is malfunctioning; and
send a fourth notification to the user device that the outdoor fan is malfunctioning.

5 . The system of claim 4 , wherein the second processor is further configured to:
in response to determining that the expected sound signature for the outdoor fan is not different from the respective sound signature of the outdoor fan determined from the first normalized outdoor unit sound data:
determine that the outdoor unit operates properly; and
send a fifth notification to the user device that the outdoor unit operates properly.

6 . The system of claim 4 , wherein the second processor is further configured to:
in response to determining that the expected sound signature for the outdoor fan is not different from the respective sound signature of the outdoor fan determined from the first normalized outdoor unit sound data:
in response to determining that the temperature setpoint is less than the value of the room temperature:
send a fourth instruction to the thermostat to set the temperature setpoint above the value of the room temperature;
capture second outdoor unit sound data for a third time period;
subtract the baseline sound data from the second outdoor unit sound data to determine second normalized outdoor unit sound data;
analyze the second normalized outdoor unit sound data to determine second sound signatures;
identify expected second sound signatures of the outdoor unit;
compare the second normalized outdoor unit sound data to the expected second sound signatures;
in response to determining that an expected sound signature for a reversing valve is missing from the second normalized outdoor unit sound data, determine that the reversing valve has failed; and
send a fifth notification to the user device that the reversing valve has failed.

7 . The system of claim 6 , wherein the second processor is further configured to:
in response to determining that the expected sound signature for the reversing valve is not missing from the second normalized outdoor unit sound data:
in response to determining that the expected sound signature for the reversing valve is different from a respective sound signature of the reversing valve determined from the second normalized outdoor unit sound data, determine that the reversing valve is malfunctioning; and
send a sixth notification to the user device that reversing valve is malfunctioning.

8 . A method comprising:
sending a first instruction to a thermostat to shut down a heating, ventilation, and air conditioning (HVAC) system; instructing a user to minimize background noise; instructing the user to go to an outdoor unit of the HVAC system; instructing the user to capture an image of a nameplate of the outdoor unit; analyzing the image to determine a distance of the user from the outdoor unit; comparing the distance to a distance range; in response to determining that the distance is within the distance range, capturing baseline sound data for a first time period; sending a second instruction to the thermostat to turn on the HVAC system; determining a value of a room temperature; sending a third instruction to the thermostat to set a temperature setpoint below or above the value of the room temperature; capturing first outdoor unit sound data for a second time period; subtracting the baseline sound data from the first outdoor unit sound data to determine first normalized outdoor unit sound data; analyzing the first normalized outdoor unit sound data to determine first sound signatures; identifying expected first sound signatures of the outdoor unit; comparing the first normalized outdoor unit sound data to the expected first sound signatures; in response to determining that an expected sound signature for a compressor is missing from the first normalized outdoor unit sound data, determining that the compressor has failed; and sending a first notification to the user device that the compressor has failed.

9 . The method of claim 8 , further comprising:
in response to determining that the expected sound signature for the compressor is not missing from the first normalized outdoor

Assignees

• Lennox Ind Inc

Inventors

• Delgoshaei Payam
• Venkatesh Sridhar
• Berg Eric

Classifications

• F24F11/49

  ensuring correct operation, e.g. by trial operation or configuration checks · CPC title

• F24F11/52

  Indication arrangements, e.g. displays · CPC title

• F24F2140/00

  Control inputs relating to system states · CPC title

• F24F11/58

  using Internet communication · CPC title

• F24F11/526

  giving audible indications · CPC title