Routine maintenance should cover the following items:
The Daikin Rooftop Packaged System Unit is an outdoor unit. However, the schedule may dictate storage either on the ground or in its final position at the site.
If the unit is stored on the ground, additional precautions should be taken as follows:
Winterizing Water Coils
Coil freeze-up can be caused by such things as air stratification and failure of outdoor dampers and/or preheat coils. Routine draining of water cooling coils for winter shutdown cannot be depended upon as insurance against freeze-up. Severe coil damage may result.
It is recommended that all coils be drained as thoroughly as possible and then treated in the following manner.
Source: Daikin (oslo.daikinapplied.com)