As I write, it’s the first day of summer and a scorcher here in Northern Colorado—103F. But, it’s a dry heat—only 10% humidity.

I know, you’re laughing, as if 103 dry is any more tolerable than a more humid 103. Actually, it is—or so the weather experts tell us.

Now that the summer heat is bearing down on cities across the U.S., millions of window-mounted air conditioners are getting a real work out. Chris Hall, president of, says his company is ready for the seasonal spike in questions from consumers who are wondering why their A/C unit isn’t working properly. In many instances, he says, consumers can rectify the problem themselves–if they have the right advice.

“More than any other household appliance, air conditioning units are often neglected. This is a pity because they are big energy users and a little maintenance means that homeowners can save money on both utility and repair bills,” says Hall, whose company provides consumers with the information and parts they need to fix their appliances themselves. “If the unit does stop working, we can often save consumers a visit from a repair technician.”

All residential window air conditioners have a cooling system consisting of four primary components: a compressor, an evaporator, a temperature sensing device, and a condenser. Air conditioner cooling systems are better understood if you think of them more as a device that removes heat and humidity from the air than a device that cools the air.

These are the essential maintenance steps you should take to keep your window-mounted air conditioning unit operating in tip-top condition while using the least amount of energy:

1. Every month during the months of operation, replace (or clean) the filter located in the front grill.

2. The condensing coils on an air conditioner get very dirty, and the dirt tends to accumulate on the inside of the coils, out of sight. Once a year, remove the entire cover of the air conditioner to gain access to the coils and then clean them by blowing compressed air on them or with a soft bristle brush.

3. Don’t despair if you’ve accidentally bent the aluminum fins on the rear of the unit. Use a handy A/C fin-straightening comb to realign those fins.

Best Inexpensive: My pick for best inexpensive window air conditioner is this Frigidaire 5,000 BTU Mini-Compact Air Conditioner. Ideal for a smaller space, like a bedroom, it’s a little workhorse. You can opt for the purchase price to include “expert set-up,” so that once it arrives, a certified handyman comes to your home and sets it up in the window and gets it up and running, pronto!


A motor is running but no air is blowing. Air conditioners have two motors: the compressor and the fan motor. It is possible that only one is running. If, after removing the cover of the unit you discover the fan blade is very stiff and difficult to rotate, the fan motor may need oiling or may need to be replaced.

Water leaks from the front of the unit. This is normal. All air conditioners should be installed so they tilt slightly backward to allow for proper removal of condensed water that accumulates.

The air smells musty. Air conditioners remove moisture from the air. Most of it is evaporated from the unit. However, it is possible for some water to stagnate in the base of the air conditioner. Also, dirt, lint or dust can collect in the water pan at the base of the unit and absorb water, allowing mold and mildew to grow. All this leads to bad smells. Thoroughly clean the water pan each year when you clean the condenser coils.

Need more help with your window-mounted air conditioners? Check, where you may find exactly what you need on this very helpful site.