The five major components of your car’s A/C system


In the northern hemisphere it is the summer season and in most of North America people are experiencing record heat. The Mobile Air Conditioning Society (MACS) Worldwide wants you to remain cool and safe in your vehicle this summer. Here is a brief overview of the components that run your car’s air conditioning system. Knowing what they are can help you be aware of potential problems that might heat things up later.

Today, most automotive A/C systems contain 5 major components. These are the evaporator, compressor and condenser, and two other items, either a receiver/drier and expansion valve (also called a thermal, or thermostatic expansion valve, or TXV for short), or an accumulator and orifice tube; which two of these four last items depends on the type of A/C system.

Automotive A/C systems also contain “minor” components, such as rubber hoses and metal piping (sometimes referred to as the “lines”), the air routing ductwork and controls, and also electrical devices such as relays, switches, electronic control units, etc. These additional components will vary by system and vehicle manufacturer.

Vehicles equipped with Automatic Temperature Control (ATC) also have a computer that handles the ATC system functions. And speaking of computers, on most vehicles equipped with computerized engine control systems (most since the early ‘80s), the engine control computer usually has some authority concerning A/C system operation. There may even be other computers having a role in A/C system operation; it all depends on the vehicle.

In any case, even though the engine control computer, or others, may not ”directly be” air conditioning system components, they must be taken into consideration during any discussion of A/C system operation, as their presence can have a great affect on A/C system service and diagnostic issues.

In the days ahead this blog will discuss each of the five major components of your car’s
A/C system and potential problems that could signal a need for professional service.

E-mail us your questions at or visit to find a Mobile Air Conditioning Society repair shop in your area. Visit to find out more about your car’s mobile A/C and engine cooling system.

 When having your mobile A/C system professionally serviced, insist on proper repair procedures and quality replacement parts. Insist on recovery and recycling so that refrigerant can be reused and not released into the atmosphere.  


About macsworldwide

Mobile Air Conditioning Society (MACS) Worldwide Founded in 1981, MACS is the leading non-profit trade association for the mobile air conditioning, heating and engine cooling system segment of the automotive aftermarket. Since 1991, MACS has assisted more than 600,000 technicians to comply with the 1990 U.S. EPA Clean Air Act requirements for certification in refrigerant recovery and recycling to protect the environment. The Mobile Air Conditioning Society (MACS) Worldwide’s mission is clear and focused--as the recognized global authority on mobile air conditioning and heat transfer industry issues.
This entry was posted in Automotive, Mobile Air Conditioning and tagged , , , , , , , , , , , . Bookmark the permalink.

2 Responses to The five major components of your car’s A/C system

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s