Heat Pumps by A. O. Smith

A fan at the top of the hybrid electric heat pump water heater pulls ambient air in from the room it resides in. The air is pulled in through an evaporator while refrigerant in the evaporator absorbs the heat from the air. The refrigerant runs through a compressor which raises the temperature and the pressure. Finally, the heated refrigerant is passed through a condenser coil that is wrapped around the inside of the tank. This helical shape ensures the most efficient transfer of the heat from the refrigerant to the water.