Carrier HH18HA279 Defrost Sensor 65-33 Degree

The Carrier HH18HA279 Defrost Sensor is a vital component in Carrier heat pump systems. It monitors the temperature of the outdoor evaporator coil, which absorbs heat from the air during defrost cycles. When the coil temperature falls below a set point, typically around 32°F, the sensor signals the defrost system to activate. This prevents ice buildup on the coil, which would impede airflow and reduce the heat pump's efficiency. Made for tube mounting, the sensor operates within a wide temperature range of -40°F to 150°F. Its compact size, measuring 4.1 inches by 3.1 inches by 1.75 inches with a thin 0.1 inch profile, allows for easy installation within the HVAC unit.