Reply: Costs have risen because the EPA has its head in the clouds, in a manner of speaking. It has to do with the suspected depletion of the earth's ozone layer by man-made chlorine and fluoride compound gases (CFCs) that get released into the atmosphere. CFCs are widely used as refrigerants in air conditioning and heat pump systems.

Most industrial nations have agreed to reduce and eventually eliminate CFC emissions. In the U.S., these policies are embodied in the Clean Air Act, which the EPA enforces. One of the things the EPA is cracking down on is the release of CFC gases from a/c system leaks and purges.

In the old days if an a/c system got low on refrigerant the technician merely added some more and that was the end of it. Now, he is required to look for the leak and then repair it. This takes time. If he is doing a major repair that requires evacuation of the refrigerant gas, he cannot simply vent it into the surrounding air the way he used to. Instead, he must use special equipment that captures the CFC for recycling or destruction. Technicians must be trained and certified to perform these tasks. All this adds expense.

At the moment a/c firms are operating under interim EPA regulations. These rules are hazy about how to handle various situations that arise in the field. Because of the confusion, the tempthe temptation is great to ignore the rules altogether. After all, CFCs are non-toxic, odorless and invisible. Who would know if a technician releases them into the atmosphere?

Reputable operators think twice about succumbing to these temptations, however. The EPA has authority to levy fines of up to $10,000 - applicable to homeowners as well as service firms - for allowing CFC gases to escape into the atmosphere, and they have been aggressive in enforcing the CFC regulations. Besides, our planet's environment is at stake.

Any good seasonal maintenance service should include tests of system performance that might indicate a leak of refrigerant. Seasonal maintenance also should include cleaning both the inside and outside coils, replacing the filter, oiling the blower motor and checking the contact points on electrical relays. Annual springtime maintenance should be sufficient in northern areas. In hot climates with year-round a/c use it's a good idea to service the unit twice a year or even quarterly.

Low refrigerant levels aren't the only cause of poor performance. It could be a sign of mismatched evaporator (inside) and condensing (outside) coils. In recent years many homeowners have upgraded to new high-efficiency heating-cooling systems, but replaced only the indoor or outdoor portion. The trade publication Air Conditioning, Heating & Refrigeration News reported that in nearly 50 percent ocent of replacement installations, the evaporator coil does not match the condensing unit. Mismatched systems will function but with a penalty of reduced performance and system life.