If you've ever lost your air conditioning on a hot summer day, then you know what a big difference a little cool air makes. The best way to tell if your air conditioner has a problem is if it can't generate or maintain air temperatures that are 50 degrees Fahrenheit (10 degrees Celsius) below the ambient outside air temperature.

The most common cause of a malfunctioning air conditioning unit is a low level of refrigerant. This could be caused buy a leak somewhere in the system. Since modern air conditioning systems are complicated creatures, it's best to have a professional check out the problem.

The air conditioning maintenance industry has changed a lot since 1994, when the Federal government outlawed the use of a refrigerant called R-12, known by its brand name Freon. In the past, if your air conditioner wasn't blowing cool air, you'd head down to the service shop, they'd top your car off with a little Freon and you'd be on your way.

The problem is that Freon, a chlorofluorocarbon, is extremely destructive to the ozone layer. Most people needed Freon refills because they had leaks. By simply refilling the leaky air conditioning units, millions of pounds of Freon were entering the atmosphere every year.

If your car was built before 1994, then you need to have your refrigerant checked out by a licensed professional who knows how to dispose of or recycle the material. In some states, it's illegal to refill a leaky system with R-12. However, even older cars can be easily retrofitted to use the newer, safer type of refrigerant called R-134a.

For even more car maintenance and service tips, check out the links on the next page.