Frost remidiation and frost sensor

Patent metadata

Field	Value
Publication number	US-12410926-B2
Application number	US-202217957347-A
Country	US
Kind code	B2
Filing date	Sep 30, 2022
Priority date	Oct 5, 2021
Publication date	Sep 9, 2025
Grant date	Sep 9, 2025

Abstract

A heating, ventilation, and air conditioning (HVAC) system includes a closed loop refrigeration circuit including a heat exchanger assembly, a detection assembly operable to detect refrigerant from the closed loop refrigeration circuit mixed with air, a mitigation device operable to monitor at least one parameter associated with operation of the detection assembly and a controller operable to determine if an alarm generated by the detection assembly is a false alarm in response to the at least one parameter monitored by the mitigation device.

First claim

What is claimed is:

1. A heating, ventilation, and air conditioning (HVAC) system, comprising:
a closed loop refrigeration circuit including a heat exchanger assembly;
a detection assembly operable to detect refrigerant from the closed loop refrigeration circuit mixed with air;
a mitigation device operable to monitor at least one parameter associated with operation of the detection assembly to detect if frost is present at the detection assembly; and
a controller operable to both the detection assembly and the mitigation device, the controller being operable to determine if an alarm generated by the detection assembly is a false alarm in response to the at least one parameter monitored by the mitigation device.

2. The HVAC system of claim 1 , wherein the mitigation device is a temperature sensor.

3. The HVAC system of claim 2 , wherein the at least one parameter is an ambient temperature.

4. The HVAC system of claim 1 , wherein the at least one parameter is correlated with a temperature.

5. The HVAC system of claim 1 , wherein the mitigation device is a camera.

6. The HVAC system of claim 5 , wherein the at least one parameter is a visual appearance of the heat exchanger assembly.

7. The HVAC system of claim 1 , further comprising:
a blower operable to move a flow of air across the heat exchanger assembly; and
a thermostat operable to generate a signal indicating a temperature demand of an area to be conditioned by the HVAC system, wherein the blower and the thermostat are operably coupled to the controller.

8. The HVAC system of claim 7 , wherein the HVAC system is operable in a first mode when the detection assembly generates an alarm and the HVAC system is operable in a second mode when the detection assembly generates the false alarm.

9. The HVAC system of claim 8 , wherein in the first mode, the blower is operational and the thermostat cannot communicate heating and cooling calls to the controller.

10. The HVAC system of claim 8 , wherein in the second mode, the blower is operational and the thermostat is configured to communicate heating calls to the controller.

11. A method of operating a heating, ventilation, and air conditioning (HVAC) system comprising:
generating an alarm indicating a refrigerant leak in the HVAC system via a detection assembly;
monitoring a parameter associated with the detection assembly via a mitigation device in response to generating the alarm indicating a refrigerant leak in the HVAC system, wherein the parameter indicates a presence of frost at the detection assembly; and
determining that the alarm is false in response to the parameter.

12. The method of claim 11 , wherein in response to determining that the alarm is false, actively defrosting the detection assembly.

13. The method of claim 12 , wherein actively defrosting the detection assembly further comprises blowing a flow of warm air over the detection assembly.

14. The method of claim 12 , wherein a thermostat of the HVAC system is configured to communicate a heating call to a controller of the HVAC system during the actively defrosting the detection assembly.

15. The method of claim 11 , further comprising:
operating a blower of the HVAC system and restricting communication of heating and cooling calls from a thermostat to a controller of the HVAC system in response to determining that the alarm is a real alarm.

16. The method of claim 11 , wherein determining if frost is present at the detection assembly further comprises detecting an ambient temperature.

17. The method of claim 16 , wherein when the ambient temperature is less than 0° C., determining that the alarm is false.

18. The method of claim 11 , wherein determining if frost is present at the detection assembly further comprises monitoring a visual appearance of a heat exchanger assembly of the HVAC system.

19. The method of claim 18 , wherein determining that the alarm is false further comprises determining that the visual appearance of the heat exchanger assembly includes frost accumulation.

20. The method of claim 11 , wherein determining if frost is present at the detection assembly is initiated in response to generating the alarm.

Assignees

• Carrier Corp

Inventors

• Hovardas Sotiri
• Piech Marcin

Classifications

• F24F2110/10

  Temperature · CPC title

• F24F11/77

  by controlling the speed of ventilators · CPC title

• F24F11/38

  Failure diagnosis · CPC title

• F24F2130/00

  Control inputs relating to environmental factors not covered by group F24F2110/00 · CPC title

• F24F11/52

  Indication arrangements, e.g. displays · CPC title