APPLIANCES : Tips to Keep Air Conditioner Humming Happily

An air conditioner not only cools but also removes moisture, filters dirt and dust, and replaces stale air with fresh.

An air conditioner works on the principle that a liquid refrigerant absorbs heat (cools the room) when it expands into a gas, then gives off heat (to the outdoors) when it is again compressed into a liquid.

Room air conditioners are labeled with an Energy Efficiency Ratio (EER). When buying a new room unit, select one with an EER of 9 or higher.

Here are some tips to ensure cost-efficient operation of a room air conditioner:

* Install the unit away from exterior doors to prevent drafts and cross-ventilation that will warm the cooled air.

* Put it in a window that receives little or no direct sunlight.

* Seal or weatherstrip all gaps around the air conditioner and around exterior doors and windows.

* Make sure there are no obstructions, such as drapes or chairs, in front of the unit.

* Direct the vents upward to direct cool air to the upper part of the room. Cool air drifts down naturally because it is heavier than warm air.

* If you live in a high-pollution area, have a serviceman give the unit a chemical or steam cleaning at least once a year.

* Clean or replace the filter monthly. To remove it, follow directions in the owner’s manual. On many models, it is attached to the inside of the grille. Wash a reusable filter in detergent and water, then rinse and squeeze the excess water between newspapers and reinstall. Replace torn filters and disposable ones made of fiberglass.

* With the filter out, vacuum all accessible surfaces. If the aluminum evaporator fins are bent, gently straighten them with a plastic spatula. The fins are sharp. Be careful not to cut yourself.

* Also clean the grille, using a soft cloth, mild soap and warm water. Don’t use waxes or cleaners. Keep insect sprays away; solvents may corrode the grille.

Here are some trouble-shooting tips:

Does not run: Check the outlet with a working lamp. If it does not light, replace the fuse or reset the circuit breaker in your home’s central service panel. Do not plug any other appliance into the same circuit as the air conditioner.

Fan runs but unit does not cool: Condenser fins on the outside of the unit may be clogged with dust. Vacuum them.

Unit cools poorly: Seal air gaps between the unit and the window, and between window sashes. Wash or replace a filter that is clogged with dust. Straighten bent evaporator fins. Check the ventilator door that lets in fresh air; it may be stuck in an open position.

Excessive noise: Tighten screws on trim or exterior panels. Secure window mounting supports. If the window rattles, insert wooden wedges or pieces of folded cardboard between the window and the window jamb.

Unit frosts up: Do not use the unit when the outdoor temperature is below 70 degrees. Also check for a clogged filter.

Moisture drips into room: Tilt the cabinet toward the outdoors by a reading of a quarter bubble on a spirit level.

Bad odor: If there is a musty odor, use a wire to unclog the drain hole in the base pan. An oil or tobacco smell means the evaporator fins need to be vacuumed.