Ceiling, floor and wall insulation, weather stripping, plug and switch-plate gaskets, attic fans, double pane windows, mylar window film, window awnings and pull-down shades all assist in minimizing heat gain in the summer and heat loss in the winter.

A simple cooling system maintenance check can save you further money and energy, while improving comfort.

There are two basic types of air conditioning systems: water coolers and refrigeration units (central and wall mount).

With water coolers, tap water is pumped through filters that surround a high speed squirrel-cage fan that is belt-driven by an electric motor. As the fan blows air through the filters the water running through them evaporates. As water evaporates it cools and the temperature of the air in the house is reduced.

For maximum efficiency in a water cooler system, be sure that the filters through which the water travels are cleaned before each operating season. Grimy, dirt-filled filters reduce air flow and tax the fan motor, resulting in energy waste. Also, the drive belt between the motor and fan should be adjusted, if necessary. If it is too tight, no energy is wasted, but it will wear out more quickly. If it is loose, the motor will spin more than is necessary wasting energy.

Air conditioners that use refrigeration rather than water evaporation must also be maintained for maximum operating efficiency. The average refrigeration unit is designed to cool the inside of the home to approximately 10 degrees lower than the ambient exterior temperature. With the refrigeration unit, gas filled coils are fan cooled at the exterior and the cooled gas is circulated to the interior where another fan blows air across the cooled gas. The result is refrigerated air. Window units are the best example of this process. On the inside of the home, cool air is felt as it passes around the cooled coils. On the outside, warm air is in evidence as the air passes over the coils.

With central air-conditioning systems, the cooling-coil unit is inside the home attached to the furnace. The furnace fan is what circulates the air over the cooled coils and then through the duct work. And the unit that cools the gas generates hot air is on the outside of the house in a separate location, usually in a place where operating noise is least bothersome. Refrigerant gas, usually freon, travels between the two units via a copper line sometimes referred to as the refrigerant line.

Minute leaks in the system can allow the refrigerant to escape. When this happens more electricity will be used with less cooling effect. Have the refrigerant level checked every year or two. Also, if those funny paper-thin metal separators on the exterior portion of the system are bent, efficiency is reduced because air flow is diminished. If bending occurs, use an old dinner knife or thin-bladed screwdriver to straighten out the fins. It isn't important that the fins look nice only that air passes freely between all of them.

If you are considering the purchase of a system, the refrigeration type is a bit more expensive to purchase and operate than a water cooler, but refrigerated air is more healthful for those with allergies and produces little or no humidity.