Air conditioning systems come in many different sizes that provide for many different applications. Central air conditioning systems keep an entire home or business at a comfortable temperature, while window mount air conditioner applications do the same for smaller areas like bedrooms. Central air conditioning works together with forced air furnaces and requires the installation of a cased coil (evaporator) in the furnace which connects to a condenser on the outside of the home. Central air conditioners run on electricity and remove heat from the air using basic refrigeration principles. When the thermostat signals the air conditioning system that the temperature needs to be lowered, this begins a series of events.
First the furnace kicks on drawing air from the room through the return air ducts and pushes it out through vent ducts within the home or business. Unlike during the winter months when the thermostat calls for heat, the furnace burner does not fire. At the same time the condenser outside starts to circulate refrigerant through its compressor to the evaporator in the furnace. The air passes through the furnace and over the evaporator that is connected to the condenser. This is where the principles of refrigeration come into play.
The refrigerant receives and releases heat as it increases and decreases in temperature and changes from a liquid to a gas and back to a liquid. The air conditioning refrigerant becomes especially cold as it passes through the coil in the furnace.
As the warm air in the home passes across the cold coils the refrigerant absorbs so much heat that it turns back into a vapor. The vapor then travels back to the condenser outside where it is pressurized by the compressor and sent through the outside coil where the heat is dissipated.