HVAC system leak detection

A method of operating a heating, ventilation, and air conditioning (HVAC) system, the method comprising:

• monitoring a refrigerant pressure in a low-pressure subsystem of the HVAC system for a period of time after operation of a compressor is stopped with a controllable valve closed, wherein the controllable valve is positioned in a refrigerant conduit connecting a condenser to an evaporator;
• determining a rate of change of the refrigerant pressure in the low-pressure subsystem for the period of time;
• and
• determining whether a leak location of the refrigerant is in the low-pressure subsystem of the HVAC system or a high-pressure subsystem of the HVAC system based at least in part upon the rate of change of the refrigerant pressure in the low-pressure subsystem.

A controller of a heating, ventilation, and air conditioning (HVAC) system, the controller comprising:

• an input/output interface configured to communicate with:
• a compressor of the HVAC system;
• a controllable valve positioned in a refrigerant conduit connecting a condenser of the HVAC system to an evaporator of the HVAC system;
• and
• a pressure sensor operable to measure a refrigerant pressure in a low-pressure subsystem of the HVAC system;
• and
• a processor communicatively coupled to the input/output interface and configured to:
• monitor the refrigerant pressure in the low-pressure subsystem of the HVAC system for a period of time;
• determine a rate of change of the refrigerant pressure in the low-pressure subsystem for the period of time;
• and
• determine whether a leak location of the refrigerant is in the low-pressure subsystem of the HVAC system or a high-pressure subsystem of the HVAC system based at least in part upon the rate of change of the refrigerant pressure in the low-pressure subsystem.