Which of the following best describes "defrost mode" in a heat pump?

Defrost mode in a heat pump is primarily a function designed to reduce ice buildup on the outdoor coil. During the heating cycle, especially in colder conditions, moisture can freeze on the coil, impeding airflow and reducing heating efficiency. When the outdoor temperature is low and humidity is present, the heat pump detects frost accumulation and automatically switches to defrost mode.

In this mode, the system temporarily reverses the refrigeration cycle, directing warmer refrigerant to the outdoor coil to melt the ice. This process allows the heat pump to maintain efficient operation and optimal performance, ensuring that it continues to provide heating effectively.

Utilizing defrost mode is essential for preventing ice build-up that can lead to system inefficiencies, increased energy use, and potential damage to components.