During the defrost cycle, what typically happens to the outdoor fan?

During the defrost cycle of a heat pump, the outdoor fan is typically turned off to allow the system to effectively remove ice or frost buildup from the outdoor coil. When the heat pump goes into defrost mode, it reverses the refrigeration cycle to supply heat to the outdoor unit. By turning off the outdoor fan during this process, the system prevents cold air from continuing to flow over the coils, allowing warmer refrigerant to raise the temperature of the coils and melt any ice that has formed.

This practice is crucial to ensure efficient defrosting, ensuring the heat pump can maintain its heating capabilities without losing warmth through the fan operation. Additionally, when the outdoor fan is off, it helps concentrate the heat being released from the refrigerant into the outdoor coil for more effective ice removal.