Defrost duration: how long it should last and when it is considered excessive

A defrost cycle should last only as long as needed to clear the external exchanger without unnecessary heat loss to the building.

Normal duration

The actual duration depends on the model, the amount of ice, and external conditions.

Very short defrost

If it terminates before the ice has melted, ice may accumulate from cycle to cycle.

Very long defrost

This may indicate a sensor problem, insufficient heat transfer, or incorrect control logic.

What we record

Start time, duration, external coil temperature before and after, and time until the next defrost.