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Air conditioners need regular tune-ups

Dear Jim:We have central air-conditioning as well as a window unit in my workshop. Neither of them cool s as well as when they were new. Are there any simple tune-up items that I can do my-self? -- Sean L

Dear Sean: There are several simple things you can do to improve, or at least maintain, the efficiency and cooling output. You should be able to cut your cooling costs by about 5 percent to 10 percent with only 30 minutes of work.Central air conditioners require periodic professional maintenance like Freon pressure tests. At the least, have it checked every two years.

This will lower your electric bills and minimize costly repair problems.

An outdoor central air conditioner unit is a fairly simple piece of equipment. There is a compressor, some coils and a fan to draw air through the coils. Basically, Freon in the coils draws heat from inside your house and gives it off to the outdoor air blowing through the outdoor coils.

For peak efficiency, it is imperative to have as much outdoor air as possible blowing through the coils. More air flow can draw more heat from the coils, so your central air conditioner can provide more cooling output with less electricity. This is especially important on hot afternoons.

First, shut off the electric power to the outdoor unit. Do this at your main breaker panel or at the unit itself. Switch it off at both places to be safe. Remove the sheet metal screws and then the outdoor cover.

Spray it off with water. Try to avoid a direct water shot on the controls.

If any condenser coil fins are bent over, straighten them with the tip of a sharp knife. Make sure to tighten all the screws when replacing the cover. This is important so that the fan draws the outdoor air through the coils and not through gaps in the cover pieces.

Shrubs around the unit are good for shade and to cool the nearby air; however, keep them pruned for at least two feet of clearance. Also consider building a shade/storage bin cover. It will provide shade and keep out debris. Leave plenty of clearance above the condenser unit.

Go indoors to clean off the evaporator coils in the blower (furnace) unit. Remove the sheet metal side. Gently clean the coils with your vacuum cleaner brush. Do the same on the coils on your window air conditioner. Slip it out of the window and remove the cover for access to the coils.

While the cover is off the blower unit, check the motor for oil cups over the bearings at each end. Squirt in a few drops of bearing oil. If your model has a blower belt, adjust it to flex about 1/2 inch in the center.

Write for (or instantly download -- www.dulley.com) Update Bulletin No. 694 -- instructions for central and window air conditioner tune-ups and for making a shade/storage bin and a troubleshooting guide. Please include $3 and a business-size SASE.

James Dulley, Deseret News, 6906 Royalgreen Drive, Cincinnati, OH 45244

Dear Jim: We are planning to reroof our house with fiberglass shingles.

We currently do not have any roof ventilation. Is it better to install several round vents along the roof or a continuous ridge vent? --Tom W.

Dear Tom: A continuous ridge vent is always better than separate round vents for several reasons. It eliminates hot air pockets in the attic that do not vent. There is also less chance of water leaks with a ridge vent.

Some people think that a ridge vent is difficult to install. The long vent pieces and roll type are specifically made for this purpose. They are easy to install, especially since you are having your house re-roofed anyway.

You can take an online Open House tour of James Dulley's own house and see all the money-savings improvements and products that he tests in his own home. There are nearly 100 pictures with links to the various columns that describe the improvements and products.