Q • I have a 3-year-old 6500-BTU window air conditioner that I use to cool my apartment's living/dining room and entrance hall. The problem is that it is not cooling very well, and I see ice building up. Is there anything I can do myself to make my air conditioner work better?
There may be a couple of things that we need to look at here. First, are you using the correct size air conditioner? You mention that your AC is 6500 BTUs, but you did not say how large that living room and entrance area is.
A 6500-BTU window unit should be able to handle up to 216 square feet of space. The typical rule of thumb is that an AC should be able to efficiently cool one square foot for every 30 BTUs, so you may want to measure the square footage of your living space.
More likely, your AC may just need a good cleaning. Most people buy a window air conditioner, plug it in and forget about basic maintenance. Air conditioners have filters, coils and drains that can get dirty and clogged. A really dirty unit will even get ice buildup on the coils. Dirty coils and filters will make the unit work harder and decrease the efficiency of your AC. The fins on the exterior of the air conditioner can become a catch-all for debris, and the drain hole can become clogged. All of these are relatively easy to maintain.
Start by removing the front of the unit, unscrewing the sides as needed. The first step is to clean the thin spongy filter. Remove the filter. Wash it in warm, soapy water and set aside to dry. Now move to the exterior fins on the exterior of the unit. These need to be cleaned at least once per year. Dirt gets in fins and doesn't allow the heat from inside the house to escape. Use a clean paint brush to loosen and remove any debris. If the fins appear dirty and greasy, your local home improvement center or hardware store sells a foaming cleaner that can be sprayed upon the fins and coils. The blast of cleaner will reach your coils, and the detergent will remove buildup. Make sure the unit is off. Spray the fins with the cleaner. The detergent does not need to be rinsed.
After you have cleaned the fins, inspect them closely. If any fins are bent, the heat again will not escape the unit. A fin comb can be purchased from your local store or air conditioning supplier. The comb is inserted into an undamaged section of the fins and then pulled through the damaged section to straighten. Finally, look at the drain hole located somewhere in the back of your AC. This drain hole can become clogged with dirt or calcium buildup. Use a cotton swab to clean out the drain hole.
These very simple steps should improve the operation of your window air conditioner and prolong its life. Keep cool.
Dave Foster is the store manager for the Home Depot in Brentwood.