Although more and more homes have central air conditioning, about 6.5 million window units are sold each year. Our latest tests of small, medium, and large window air conditioners found that all were excellent at cooling. What distinguished the best from the rest was quiet operation, convenient controls, and whether they kept working under brownout conditions. All of our top picks exceed federal Energy Star standards and use at least 10 percent less energy than conventional models. Those energy-savers often include other features, such as timers, digital displays, remote controls, and directional vents, which coax the most comfort from the machine.
How to choose a room A/C
Before going to the store, determine the size of the space you need to cool and where you’ll place the unit. An air conditioner that's too small won't cool the room. One that's too big will cool so quickly that it won’t have time to remove enough moisture, leaving your room cold and clammy.
Get the right size. When calculating the size of the air conditioner you'll need, take into account not only the size of the room to be cooled but whether the unit will be placed in a window that gets shade or direct sunlight, the height of the ceilings, and even the part of the country where you live. The Association of Home Appliance Manufacturers has a worksheet on its website that will help you make the right determination. All you need to get started is a tape measure, a scratch pad, and a calculator.
Assess the airflow. Air conditioners generally do a better job blowing air in one direction than the other. To uniformly cool a room, you'll need to ensure that air is distributed throughout. When the window air conditioner is located near a corner, it must be able to direct air to the center, so check whether your air conditioner needs to blow air to the right or to the left.
How quiet? If the unit is going to be placed in a bedroom or another quiet area, check our Ratings for 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 or worse for noise could disturb light sleepers when set on low and are distracting on high.
Our latest tests of almost three dozen room air conditioners include an $580 model that cools superbly and quietly, and even comes in colors that match the drapes. But you don’t have to spend a lot to cool down as the mercury climbs; other top performers start at $160.