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Today, the heating and air-conditioning systems in our cars get taken for granted. We count on the heating system to keep us toasty in the winter months and the cool air from the air-conditioner to refresh us during the summer. Ever wonder how these systems work? Thanks to the service department at Suburban of Farmington, a local Chrysler, Dodge, Jeep, Ram dealer in Farmington Hills, MI, we have the whole scoop for you.

Heating Systems

As you likely know, the heat in your car comes from your engine.  Your engine is cooled by a jacket of water (plus antifreeze) that encases the piston cylinders. The hot water generated by combustion not only flows through the main radiator but also through a heater core which is basically a smaller version of your main radiator. Heater cores are usually positioned under the dash and have a fan that blows air over it. The result is nice warm air circulating throughout the car on chilly days.

To keeping it working

To keep your heating system happy, make sure it is topped off with a good brand of anti-freeze, all year long. The problem is that automotive cooling systems can corrode over the years and leak. A good brand of anti-freeze has corrosion inhibitors in it and they can prevent this from happening. Take it from the folks at Suburban, keep a good brand of antifreeze in your cooling system and save yourself from expensive repair bills.


The air-conditioning system in your car is a bit more complicated than heating systems are.  First, the physics behind air-conditioning involves complex physical laws called “Thermodynamics.” Basically, air-conditioners employ a compressor, condenser, expansion valve and evaporator to pull the hot air out of your cabin and exhaust it to the front of the car. Technically this is what happens: Refrigerant (Freon) is compressed in the compressor where it turns into a hot gas. In the condenser, this hot gas is cooled to a liquid state and travels to the expansion valve. As the Freon goes through the expansion valve it returns to a low-pressure gas and rapidly cools in the evaporator. A fan then blows over the evaporator and cool air fills the cabin.

To keeping it working

Because the system operates under such high pressure, from time to time air-conditioning systems need to be recharged. This will bring the system back up to maximum efficiency. An AC system that is low on Freon just doesn’t cool very well and you may not recognize this until the outside temperature is very hot. Today’s AC systems are complex so it is best to leave this service up to a professional mechanic.

Do you drive an older car?

In recent years, the EPA has phased out the use of R-12 Freon in all refrigeration systems. This is because R-12 is lighter than air and floats skyward where it disrupts the Earth’s ozone layer. The EPA has severely restricted the sales of R-12 to the point where it actually gets sold on the black market. The new refrigerant used in all vehicles is R-134.  If you have an older system with R-12 you may need to retrofit your system to handle the new R-134 refrigerant. Sometimes seals, hoses and even the compressor need to be changed. The problem arises when the older seals and hoses are not compatible with the new oils found in the R-134.


If you want to get maximum use out of your car’s heating and cooling systems, remember to apply some preventative maintenance. As we discussed keep your antifreeze topped off and flush your cooling system every few years. With your AC system, make sure it has the right amount of R-134 in it. This can be checked by any certified automotive mechanic.

Earthgarage – Greener Car. Fatter Wallet.