In heating mode, when the outdoor fan shuts off during defrost, what is the primary goal?

In heating mode, the primary goal when the outdoor fan shuts off during defrost is to facilitate defrosting. During the defrost cycle, the system temporarily reverses operation to heat the outdoor coils, melting any accumulated frost or ice. Shutting off the outdoor fan during this phase helps direct warm air to the coils, improving the effectiveness of the defrosting process by allowing the heat to focus on melting the ice rather than dispersing it through the fan.

This targeted heating is essential because ice build-up can impair the system's efficiency and reduce its heating capability. By ensuring that the heat is applied directly to where it is needed, the system can effectively clear the coils, allowing the heat pump to resume normal operation more quickly and efficiently. Thus, the main objective of shutting off the fan during defrost is to ensure a successful defrost cycle, improving overall performance.