How often should defrost cycles occur in HVAC systems?

The frequency of defrost cycles depends on various factors, including outdoor temperature, humidity, and system design. In general, defrost cycles should occur every 30-60 minutes, with a duration of 10-30 minutes, depending on the type of defrost system and system requirements. However, the optimal defrost cycle frequency and duration may vary depending on specific system conditions and should be determined during the commissioning process.