Air Conditioner System Requirements

Compressor and Condenser

• Every air conditioner, regardless of size or type, contains a compressor and condenser. These devices are located on the outside of the fan intake system but inside the housing of the air conditioner. The condenser contains a low-pressure gas that the compressor compresses into a hot or high-pressure gas. The gas flows into the condenser, which pulls away heat and rapidly cools the gas into a liquid. The liquid travels into an evaporator, where the pressure drops and the liquid reverts into a gas. During that process, the gas soaks up the surrounding heat, cooling the air that passes over it before entering the ducting and then the house ventilation system.

Intake

• All air conditioners require an intake. This is where air enters the unit for cooling. Large, whole-house air conditioners require the largest intakes, as the volume of air is much greater than window units. Air is sucked into the air conditioner using a metal fan that typically rotates at various speeds and is controlled via a control on the thermostat inside the house. Air conditioners require fresh outdoor air to operate properly and usually do not recirculate air from inside the house.

Exhaust and Ducting

• Just as an air conditioner requires air from outside, it also requires a way to vent hot air created by the compressor and condenser. Air conditioners actually create just as much hot air as they do cold air, so having a vent for the hot air to escape is critical. In whole-house systems, the air conditioner sits outside and acts as a natural vent. Window units mount on the windowsill, halfway inside and halfway outside, to allow the venting hot air to come out of the back of the unit. Portable air conditioners that sit inside the house must be connected to a window via a vent tube, or else the hot air will escape into the house and negate the cooling effects.

Heat Pumps

• Some air conditioners act as heaters, given their efficient production of both cold and hot air. However, heating air conditioners also require a heat pump. The heat pump is a valve that sits between the air conditioner and the hot side of the condenser. When the thermostat is set to heating mode, the valve turns to allow the hot air from the condensing process to enter the home instead of the cold air. But because this process can actually freeze parts of the air conditioner, most heating units also contain an electric heating element to warm the cold parts of the appliance when in heating mode.