Heating Mode


In the heating mode, hot refrigerant flows through the air coil.  The heat pump supplies warm air to the conditioned space.  The heat added to the room air is removed from the water flowing through the coil, plus the rejected compressor heat. (See Figure 1 below.)

Cooling Mode


In the cooling mode, cold refrigerant flows through the air coil. The heat pump supplies cool air to the conditioned space.  The heat removed from the room air is transferred to the water flowing through the water coil. (See Figure 2 below.)

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