We all know how air conditioning works. You push a button and cold air comes out of a vent.
Okay, it’s actually a bit more complicated than that.
Air conditioning is based on a basic principle of physics: When something is compressed, it gets hot, and when pressure is released, it gets cold.
(Have you ever used an aerosol spray and felt the can get cold in your hand? The sense of cold comes from the pressure inside the can being released as you spray. Same principle.)
An air conditioner starts with a looped pipe filled with a refrigerant, a chemical that changes from liquid to gas and then back to liquid at close to room temperature. For many years, air conditioners and refrigerators used Freon for this purpose. Now they use the chemical R410A, which is more environmentally friendly. The refrigerant is moved through the pipe by a pump called a compressor.
Opposite the compressor is a nozzle called the expansion valve. This valve limits the amount of fluid that can flow through the pipe at this point, causing excess refrigerant to back up behind it, like water behind a dam.
As the refrigerant backs up behind the expansion valve, pressure forces it to turn from a gas into a liquid and, at the same time, get hot. Then, when the hot liquid finally moves through the narrow expansion valve, pressure is released, and it turns from a hot liquid back into a gas, cooling as it does so.
In a typical forced-air conditioning unit, the compressor is located in a unit outside the house. The hot, pressured refrigerant passes through a series of loops called a condenser. A fan blows air over the condenser, transferring heat from the tube into the air and out into the environment. The cooler but still condensed liquid then goes into the house, through the expansion valve, and the resulting cold gas moves through another series of loops called the evaporator. The evaporator usually sits atop a home’s furnace to take advantage of its fan. This fan blows cold air off the evaporator and into the house via the air ducts.
The refrigerant gas then goes back into the compressor where it’s turned into a hot liquid, and the heat exchange cycle starts all over again.
See? That was pretty simple after all!
Learn to Be an HVAC Technician at WyoTech in Long Beach
Air conditioning is critical to people who live and work in most parts of the United States. If you’re interested in a career in this field, you can get training in Heating, Ventilation and Air Conditioning (HVAC) at WyoTech in Long Beach. WyoTech in Long Beach has an HVAC career training program you can complete in as little as nine months. Schedules are flexible, and can include evening and weekend classes. Instructors are all industry professionals. Classes are “hands-on” in a modern workshop setting that simulates typical residential environments.
After graduation, you can get help from WyoTech’s Career Services professionals who will help you with everything from writing a winning resume to identifying and contacting local employers.
Financial aid is available for those who qualify.