BRAKEmax Blog
How your car’s AC works

Published on May 17, 2017 by

Tucson is starting to heat up again so it’s a good time to discuss how your car’s AC system works.

Your system is much more than just an air compressor – it’s a system of components which make use of four principles: compression, condensation, expansion, and evaporation.

The compressor is driven by the engine via a serpentine or drive belt.  When you click the ‘A/C’ button on your dash, the compressor starts to pump refrigerant (R134a, in most cases) under incredible pressure (up to several hundred PSI) to a condenser.

The condenser is a series of very narrow channels through which the refrigerant is pumped.  The gas ‘condenses’ into a liquid.  As it journeys through the condenser, the heat escapes through the fins and helps to cool down the refrigerant.  Air flowing through the fins (like from your car’s fans or the process of driving) help to further dissipate heat.

The now-liquid refrigerant then continues through the expansion valve, which restricts the flow of the liquid as it heads to the evaporator.

Now traveling through the evaporator, the now-cool refrigerant vaporizes.  The evaporator helps to absorb heat from the car and collects humidity which condenses on the cold surface of the evaporator.  The part becomes very cold – a fan helps push cold air through it, cooling it as it travels through the vents in our dash.

Now that you know how your A/C works, maybe stop by your local BRAKEmax for $9.99 AC Service Special.


This article was written by . Jeffry has worked with internet technology and graphic design for most of his life. He came to BRAKEmax in May of 2012 after a 7-year stint operating a local automotive service center. He married his wife Kerri in 2006; they have a son, Maxwell, and a daughter, Abby. When he's not at work, Jeffry enjoys cheering for the greatest sports team in the world, the Denver Broncos.

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