Ever wondered how air conditioning systems pump out the chilly air from their guts? Here’s a basic explanation of how they cool homes (and heads) during the sweltering summer season.
In a central heating and cooling system, an air conditioner basically works like a human heart— absorbing warm air and pumping out cold air through an intricate system of ductworks. A fully functioning central cooling system has four main parts: the evaporator, compressor, condenser, and expansion device.
The evaporator is where a special liquid, called the refrigerant, does its magic. It is considered the “lifeblood” of the entire system, as it is the main working fluid, along with the mechanical devices inside an air conditioning unit, responsible for the thermal exchange. This exchange involves mainly converting temperature and humidity into conditioned air.
In plain terms, the cooling from an AC unit works this way: As the warm air passes over the evaporator coils, the refrigerant inside absorbs the heat and humidity, thus somewhat cooling the air in the room. An evaporator fan helps move the hot interior air into the unit to blow across the evaporator coils. Inside the evaporator, the working fluid goes through a heat exchange, which converts the liquid to vapor, taking the absorbed heat with it. In the closed system of coils, the refrigerant gas is then moved into the condenser where the refrigerant gas is compressed in another heat exchange process. This converts the refrigerant gas to liquid, helped along as heat (previously absorbed from the cooled space) is discharged outdoors through the condenser fins.
The cycle continues again and again until the room reaches the preferred cooling temperature, which is controlled in real time by the thermostat.