A/C Basics: Understanding How the System Keeps You Cool
Central air conditioner systems consist of an indoor and outdoor unit connected via wires and tubes threaded through a hole in your home’s wall. The indoor unit contains components such as the evaporator and the air handler. The outdoor unit houses the compressor and condenser.
Air conditioning works on a concept of heat transfer, or more specifically, heat capture and release. This process requires a refrigerant, which is a liquid substance that circulates between the indoor and outdoor unit. During a cycle, the refrigerant changes state from liquid to gas. When it evaporates into a gas, it absorbs heat; when it condenses back to liquid, it releases that heat.
How an A/C Works
In the evaporator, the refrigerant is turned into a gas. It absorbs heat and creates a cold surface on the evaporator. The blower or air handler circulates air over the evaporator, creating the chilled air that cools your home. The cool air is forced into the ductwork, where it travels to and exits from vents throughout your living spaces.
The compressor provides the pumping action that moves the gaseous to the outdoor unit and the condenser. In the condenser, the refrigerant is pressurized, which returns it to its liquid state. As it changes state, the refrigerant releases the heat it contains. The condenser coils become hot, and another fan blows air over the condenser coils to help disperse the heat.
Indoors, the return ductwork brings expended air back to the air conditioning unit to be cooled and re-circulated. In the process, the air flows through the system’s air filter, where the filter removes particles of dust, dirt, pollen, fibers and other material that could lower your indoor air quality.
Outside, the liquid refrigerant is circulated back indoors, where the cycle of heat transfer through evaporation and condensation begins again.