Having a basic understanding of how your AC unit works though will help you to better identify the source of a problem if and when a malfunction occurs, and whether or not you need to call a professional AC repairman.
There are a lot of small but necessary parts that make up what we simply refer to as the air conditioner.
While you certainly don’t have to know each and every one of them, there are four most critical parts of a central AC system. The four main most critical parts of a central AC system are the evaporator, condenser, expansion valve, and compressor. The evaporator is located on the cold side of the air conditioner and is paired with a fan that blows air over the chilled coils and into the home. The evaporator receives the liquid refrigerant and converts it to gas through a drop in pressure. The condenser works the opposite and converts the evaporated refrigerant back into a liquid through a process known as heat transfer. In most central AC units, condenser coils are housed in the outside unit and look like a radiator in a car engine. In between the evaporator and condenser coils is the expansion valve, which is responsible for removing pressure from the liquid refrigerant to allow the conversion into gas that occurs in the evaporator. Last but not least, the purpose of the compressor is to re-pressurize the refrigerant gas in order to turn it back into liquid. So the compressor assists the condenser, while the expansion valve assists the evaporator.