Bronco Plumbing Heating and Air Blog

How Air Conditioning Works: A User's Guide

October 22, 2014

For many of us, our domestic comfort during the summer comes by way of a large, complex central air unit, heat pump or ductless mini split, which afford us unprecedented control over the temperature inside our homes, no matter how hot and humid it is outside. But despite the fact that you know your way around a thermostat, you may find the concept of air conditioning to be a bit obscure, mysterious or otherwise unknown. Where does that cool air come from? Does it work just like a refrigerator? What do the various components do?

Like any system that comprises multiple components, materials and mechanisms, your air conditioning system is only as good as the sum of its parts. If one aspect of your system is faulty, then the rest will not work effectively, efficiently, or perhaps even at all. The basic principle of air conditioning is that changing the pressure of a substance also changes its temperature. Refrigerant, a chemical compound designed to undergo radical shifts in temperature under varying pressures, circulates through several stages of pressurization and depressurization in order to absorb thermal energy from one area and dissipate it to another.

The indoor unit of a standard central air conditioner contains the air handler, which pulls your indoor air supply through the ductwork, where it is cooled according to your temperature requirements by the cold liquid refrigerant passing through the evaporator coil. During this thermal exchange, the temperature of your indoor air causes the refrigerant to evaporate into a low pressure gas, at which point it travels outdoors to the compressor unit for another round.

The compressor creates a high pressure, high temperature gas that then must be brought down again rapidly by means of blowing outdoor air through the condenser coils. As its name suggests, the condenser coil allows your refrigerant to condense into a relatively hot liquid. Not yet ready to be used as cooling, your refrigerant must be depressurized by means of an expansion valve before it reaches the evaporator coil. This is a continuous circuit that operates when you call for cooling. For further information about our air conditioning services in Sacramento, call Bronco Plumbing Heating and Air today.