All the window air conditioners in our latest tests do an excellent job of cooling and come with convenient features like digital displays, built-in timers, remote controls, or touchpad controls. But some models are noisy and others struggled to cool during brownouts. Find out which size to buy for the space you need to cool.
Low prices and high efficiency make room air conditioners an inexpensive alternative to central air for cooling one or two rooms. Some 5,000- to 6,000-Btu (British thermal units) window models now cost less than $200. Our air-conditioner guide helps you choose what's right for you.
Nearly all the window units we tested meet the latest Energy Star standards, which require them to use 15 percent less energy than the minimum allowed. And all now have electrical plugs that help prevent fires by shutting down if the power cord is damaged.
Find out whether replacing your air conditioner makes sense by using the savings calculator on the Energy Star's air conditioners page. (Every 0.1 increase in the Energy Efficiency Ratio (EER) translates into about a one percent drop in electricity use.) Also keep the following in mind:
Size it correctly
An air conditioner that's too small won't do a good job cooling a room. One that's too big cools so quickly that it doesn't have time to remove enough moisture, leaving you with a cold, clammy space.
Window air conditioners typically have cooling capacities ranging from 5,000 to 12,500 British thermal units (Btus). But don't buy by Btu alone. As a rule of thumb, an air conditioner needs 20 Btus for each square foot of living space but there are other considerations such as the height of your ceiling and the size of your windows and doorways. To measure your room, multiply the length of the room by the width. Energy Star recommends that you add more capacity if the unit is in a sunny window or if it will be placed in a kitchen.
Note the noise
Models that scored excellent or very good in our noise tests are so quiet that the only sound you might hear is the fan running. But air conditioners that scored fair for noise could disturb light sleepers when set on low and are distracting on high.
Factor in the window location
Air conditioners generally do a better job blowing air in one direction than in the other. That can be a problem if your window isn't centered on the wall. To uniformly cool a room, you'll need to direct air to its center, so check whether your A/C needs to blow air to the right or to the left. Some have fan arms that swivel.
Install it correctly
To get the most from your window air conditioner, install it right. Most units are intended for double-hung windows. If you have casement windows, you may want to consider a through-the-wall air conditioner. Make sure your window unit is level so it drains correctly. And move any heat-generating devices such as a TV or lamp away from the unit.
Make sure you can easily access the filter for cleaning, something you'll be doing frequently to keep the unit in tip-top condition.
Check the warranty
Some air conditioners have longer warranties than others. When you're buying a new unit, check the manufacturer's website for information and then ask the retailer about the warranty for that model and brand.
If you are considering central air check out our reliability report.