Know Your Car's Air Conditioning System

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The Mobile Air Conditioning Society (MACS) Worldwide wants all vehicle owners to understand their cabin climate control and engine cooling system. The following is an excerpt from the MACS' publication Get to Know Your Car's A/C and Engine Cooling System. If you have a question about your vehicle's A/C or engine cooling system e-mail us at
info@macsw.org.

 

The air conditioning in your vehicle is a sealed, high-pressure system containing a refrigerant to provide cooling. As the refrigerant moves through the system, it absorbs heat and cools the air entering the passenger compartment. As long as the system has not developed a leak, and the related mechanical components are in good shape, the air conditioning should operate properly. There is no way to determine how much refrigerant is in a system unless the existing refrigerant is removed with proper recovery equipment and the proper amount is recharged into the system. The refrigerant removal must be done in accordance with federal law by a certified technician. If the system is providing cold air, there's no need to worry about it.

 

 

Copyright MACS 2009

"There's a simple test for any A/C system," says Paul DeGuiseppi, manager of service training for the Mobile Air Conditioning Society (MACS) Worldwide. "Set all the controls for maximum cooling, close all the doors and windows, start the engine and run it for about five minutes. It's important that you have the vehicle in the shade, or out of direct sun when performing this check. If the temperature from the panel outlets gets cold, there a good chance the system is operating properly. If you have a thermometer, place it in a center outlet, and if it's a warm day and the temperature is below 50 degrees F, it's a good sign that the system is cooling."

A healthy system that operates properly shouldn't need additional maintenance," DeGuiseppi continues. "Consumers should be very careful to avoid purchasing unnecessary parts or services if their car's air conditioning is working well."

If the system is operating properly there is no need to have the system serviced. The refrigerant doesn't need to be cleaned or "refreshed" and vehicle and A/C system manufacturers do not recommend the addition of other chemicals or so-called performance enhancing additives to the system. When in doubt about using another type of refrigerant or chemical additive, consult the vehicle's service manual.

 

Anything other than the OEM recommended chemicals may void vehicle or parts warranties or cause a part to fail.

When repairs are needed, be well informed in advance. Every technician and mechanic performing A/C repairs is required by the U.S. Federal Clean Air Act of 1990 to have passed a certification test.

The U.S. Environmental Protection Agency has listed several refrigerants as acceptable for use in mobile air conditioning systems. However, only two are tested and approved by all vehicle manufacturers for use in their mobile A/C systems.

Vehicles made before 1994 most likely contain CFC-12 (R-12), a chemical that has been phased out of production because it depletes the stratospheric ozone layer that protects the earth against harmful ultraviolet radiation. Newer vehicles, after 1994, use HFC-134a (R-134a), which is less damaging to the atmosphere.

Older air conditioning systems can be switched over — "retrofitted" — to the R-134a but the change may be expensive and may require replacing components in addition to installing the new refrigerant. Although retrofitting is not required by law in the U.S. and the availability and use of R-12 is still permitted if the system is in good condition, a retrofit may prove worthwhile if expensive repairs are needed on an older vehicle.

All vehicle manufacturers and the Mobile Air Conditioning Society offer detailed technical information to service professionals on how to properly diagnose, repair and recycle refrigerants to minimize emissions and improve air conditioning performance.

Informed consumers can help reduce atmospheric pollution while keeping their cool during the hot summer months.

 

Temperatures over 90 degrees and high humidity can challenge your vehicle’s air conditioning system. Here are some easy tips to keep you and your passengers cool on the road.

 

• If possible, leave the windows down slightly on hot days to reduce heat build-up. An A/C system works by removing heat, so the cooler the interior is to start with, the easier and faster the A/C will do its job.

 

• When you get in the car, open all the windows completely, or even open the doors, for a moment to vent the hot interior air quickly.

 

• When you first turn the A/C on, set the controls to MAX or REC and use highest blower speed. This moves the greatest volume of air and re-circulates it for even faster cool-down.  As soon as you are comfortable, switch the system to NORM or OUTSIDE or FRESH, and select a lower fan speed. The lower blower speed produces colder the air from the system.

 

• Does your cool air have a bad odor, perhaps like “dirty socks” or a gym locker? Remember to set the system to the OUTSIDE air mode (not REC) frequently to help prevent or lessen this problem.

 

• Automatic Temperature Control systems operate differently than manual systems. Read your owner’s manual to gain understanding of exactly how your system works.
  With most automatic systems, the quickest cool-down comes by setting the temperature as low as it will go at first, then adjusting it later to occupant comfort.

 

 

 

Your Car's  Engine Cooling System

 

When the A/C is operated, there is additional load placed upon the engine and engine cooling system. To prevent overheating the engine during operation of the A/C system, the engine cooling system fan(s) must be properly operating and coolant level must be correct. 

If the coolant level is low it should be replenished.   However, the days of just adding some green coolant are over. Today, the coolant is chemically different for many vehicles. Keeping a cooling system in chemical balance requires the proper coolant. The wrong coolant could result in costly coolant system and engine repairs.

Today there are many different colored coolants to help identify what’s in the system. And not only is the proper coolant required, but also the proper mixture of coolant and water.

 

Learn more about the care and service of your vehicle at www.carcare.org