What is the primary function of a heat pump during its defrost cycle?

The primary function of a heat pump during its defrost cycle is to remove ice buildup from the outdoor coil. In cold weather conditions, moisture in the air can freeze on the outdoor coil of the heat pump, which can hinder its efficiency and performance. The defrost cycle temporarily reverses the heat pump's operation, allowing hot refrigerant to flow into the outdoor coil. This process heats the coil, causing the ice to melt and ensuring that the heat pump can continue to extract heat from the outside air effectively. By removing the ice buildup, the heat pump maintains optimal airflow and efficiency, ensuring that it can deliver heating to the indoor environment as intended.