The split system heat pump is a heat, air-conditioning and ventilation system (HVAC) divided between an outdoor unit and an indoor unit. The two units are connected through the house by copper piping. The outdoor unit houses a coil that acts as a heat exchanger and compressor. The indoor unit houses a coil and a fan. The fan housed in the indoor unit circulates air through the home's ventilation system. Freon gas acts as a coolant as it passes through the copper piping, between both coils (indoor unit and outdoor unit). Heat is absorbed from the air by the Freon gas.

As a heater during winter

Freon gas absorbs heat from the air moving over the coil in the outside unit. The gas heats up to temperatures over 140 degrees F by moving through the compressor in the outdoor unit. The heated gas passes into the indoor coil via the copper piping. The fan housed in the indoor unit pulls the heated air through a grill. From the grill, the hot air moves through the coil housed in the indoor unit. While the gas remains in the copper piping, its heat passes through the metal of the coil. The air from the fan passes over the coils and carries the heat to the heat ventilation ducts in the home. In essence, the split system heat pump is an air-conditioning unit that reverses the cooling process in order to warm the inside air of a home.

As a cooler during summer

Heat within the home is moved across the coil housed in the indoor unit. The Freon gas absorbs the heat from the hot air moving over the coil. Moisture and heat are removed from the air inside of the home. Freon gas carries the heat through the copper piping to the outdoor unit's compressor. As the Freon gas moves through the compressor, it then passes through the coil. The heat moves through the coil in the outside unit, which then releases the heat to the outside air.