You know how your air conditioning works – you crank the thermostat and cold air comes out like magic! Actually, there’s a little more to it. While you don’t necessarily need to understand how every component of your AC unit functions, any more than you need to fully understand your car engine, it never hurts to know the basics of the machinery you rely on. Here’s a primer on how your AC works.
The Basics of Your System
An air conditioning unit consists of three main components: the compressor, the condenser, and the evaporator. In most cases, the compressor and condenser are housed in a unit positioned outside the home, while the evaporator is located indoors, often with the furnace. This system is primed with a refrigerant gas, and when you demand cool air, the gas is turned into a liquid and then quickly back into a gas, creating a field of cold air that is pushed into your home with fans while hot interior air is vented out.
How the Compressor Works
The job of the compressor is to suck refrigerant in, subject it to extreme pressure, actually heating it in the process, and then discharge it, after which it cycles through a coil to reach the condenser.
How the Condenser Works
The condenser is designed to cool the hot, pressurized refrigerant. In some systems, the air begins to cool as it travels toward the condenser, and once there, it is further cooled by fans blowing air across the fins on the condenser. Next the are is forced through an expansion device that restricts airflow to the point that the cooled refrigerant gas is transformed into a liquid.
How the Evaporator Works
The cold, liquid refrigerant is sent on to the evaporator, where warm air from the home interior is being circulated by the blower motor. The refrigerant absorbs the heat from the air, returning to a gas form. Cooled air is then pushed through ducts into the home and the warmed refrigerant gas is returned to the compressor to start the cycle all over again.
How Far Can Your AC Unit be from Your Furnace?
Typically, your AC unit will be located outside while the furnace is located indoors. However, one component of your AC system, the evaporator, is located indoors, near the furnace. Why?
The evaporator represents the last step in the cooling process, where hot air from your home is essentially replaced with cold. This cold air must be pumped through existing ductwork, and the point at which this occurs is the same one where warm air from your furnace enters the home. The bulk of the AC unit (compressor and condenser) need not be anywhere near the furnace, but the most convenient location for the evaporator is right next to it.