Window AC units cool down fast and cheap

The sun’s been toasting for weeks now. With more hot summer days to go, you might seek relief by staying in your home.

If you have an older house or just want to keep one specific area cool, a window air conditioner is a way to cool off. But to maximize your window unit, you’ll need to keep a few things in mind when buying one.

Window air conditioners have become better in recent years, says Celia Kuperszmid Lehrman, the deputy home editor for Consumer Reports magazine, which has a report about them in this month’s issue.

“They have gotten much more efficient,” she says. “The EnergyStar-qualified models use 25 percent less power than those made before 2000. ... They’ve gotten quieter. They’re lighter, so they’re not as big of a chore to put in and take out of the window.”

In addition, many models have remote controls and digital displays, she says.

When it comes to shopping for window air conditioners, the most important thing to make sure is that the one you pick has enough BTUs (British Thermal Units) per hour to cool the area you want, say Lehrman and Jason Mendez, the seasonal department manager at Lowe’s in Fresno, Calif. In general, “the bigger the BTU (number), the bigger the square footage it’s going to cover,” Mendez says.

Units with 5,000-6,000 BTUs will cool an area of about 100-300 square feet; 7,000-8,200 BTUs will cover about 250-550 square feet; and 9,800-12,500 BTUs will cool 350-950 square feet. Getting the correct size is important, Lehrman says.

“One that’s too big (in BTUs) will use too much energy,” she says. “It’s going to turn off before it can take out the humidity (in the room), and you’ll have a cold, clammy room. If it’s too small, it’ll be running all the time and may not be able to cool the room to the temperature you want to reach.”

To help you determine the amount of BTUs your window air conditioner should have, Consumer Reports has an online worksheet you can fill out. Go to www.consumerreports.org, then click on “sizing worksheet” under “appliances.”

Another thing to keep in mind is the noise level, Lehrman says. While window air conditioners have gotten quieter, some may be quiet at low settings and noisy at higher settings, she says. Noise was one factor Consumer Reports tested for its report.

The cost of window air conditioners can vary, depending upon the number of BTUs. For example, at Lowe’s, a 5,000-BTU model costs $96, an 8,000-BTU unit is $167, and a 10,000-BTU air conditioner starts at $208.

When you find a suitable one for your use, it’s “also important to know (that) when they get their unit home, they install it in a shady spot in that room,” Lehrman says. “It’s going to increase efficiency because the sun’s not going to be beating down on it and (it won’t be) working so hard.”

Also, keep the filter clean. “You want to check it every couple of weeks,” she says. “If it’s dirty, wash it with warm, soapy water or vacuum it, depending upon the manufacturer’s directions. This will help it run well and efficiently.”