How do I select an APR Control for multi-stage/multi-circuit systems?

You will need to know total tonnage of the unit. Then the tonnage of the circuit and in particular the lead circuit (referred to as: First On/Last Off circuit). Then we need to know the tonnage of the lead compressor stage. Only one APR Control can be installed per circuit. In most cases, only one APR is needed per system. However, there are cases where an APR Control on each circuit might be beneficial…split face evaporator coils, MUA, VAV, for example.