Could Your Air Conditioner Be Making You Sick?

On a scorching summer day, air conditioners do more than help you stay comfortable indoors. They help protect against such serious maladies as heatstroke and filter out some pollutants and allergens.
Air conditioners can be especially important for people with lung or heart disease who might struggle to breathe easily when air is hot and humid, says Norman Edelman, M.D., a senior science adviser for the American Lung Association.
But without proper care and maintenance, air conditioners also have the potential to cause health problems, especially when mold grows inside them. Here, how to stay cool and healthy when using portable or window air conditioners.
Watch for Mold
Mold that finds a way into your home can cause such symptoms as throat irritation, wheezing, and congestion, according to the Centers for Disease Control and Prevention.
Living with a moldy air conditioner “would increase your chances of having a respiratory infection,” says Mark Mendell, Ph.D., an affiliate scientist at Lawrence Berkeley National Laboratory who has studied the health effects of ventilation systems. Here’s how to know whether mold has taken up residence in your air conditioner and how to prevent that from happening.
Check the angle: Make sure a window air conditioner isn’t tilted into the interior of your home. It should be tilted slightly toward the exterior, Regan says. When it’s tilted the wrong way, rain can end up inside, and the slow buildup of moisture can create mold.
Keep a portable drained: If you’re using a portable air conditioner, it most likely has a little light that will indicate when the water reservoir needs to be drained. When you see that light, open the drain plug—usually located at the bottom of the unit—and drain the water into a tub or outdoor area, Regan says. Standing water can “attract all kinds of mold,” Edelman says. During the off-season, you should store the unit drained, with the cap off, so it can air out.
Banish Bad Air
Avoid buying a window unit with a vent—a small opening that lets in air from the outside—especially if the air quality where you live might be poor, say, near a power plant or a school where buses idle.
You want to avoid letting in particulates like diesel exhaust that can cause or exacerbate health problems such as asthma and lung inflammation. Vents can also let in pollen, ragweed, and other allergens, so if you’re sensitive enough to avoid opening the windows, stay away from vents as well. (Very few air conditioners have a vent; most only recirculate air from the interior of your living space.)
You should also make sure an air conditioner’s side panels are installed snugly against the side of the window frame so that hazardous outside air can’t creep in. For extra protection, use the foam strips that come with most air conditioners and lay them across the top and underneath the air conditioner when you’re installing it to create a better seal.
Avoid Quick Temperature Changes
If you have asthma, you might experience respiratory problems if you breathe in very cold air after being out in the heat. Older people often have a hard time with extreme changes in temperature as well, according to the CDC.
Avoid these sudden shifts by decreasing the temperature gradually when you come back inside during the summer, Edelman suggests. And if you suffer from a respiratory condition, try to avoid going directly from very cold air to very hot air.

Best Window Air Conditioners for the Hot Days Ahead

All of the window air conditioners in Consumer Reports’ latest tests do a good enough job at keeping you cool. What distinguishes one window unit from another is how quickly and quietly it cools a room—and how easy it is to operate.
Even if your home has central air conditioning, you might want to consider a room unit to cool areas not served by the main system, such as a home office or a finished room in the attic. If you do, go with a window air conditioner. They’re a better choice than portable air conditioners, which struggle in our tests.
And you don’t have to pay a lot to get heat relief. Most window air conditioners in our tests range from $150 to $400. The outlier? The Friedrich Kuhl SQO8N10D, $710, a strong performer with a streamlined look.
To help a window unit run more efficiently, look for a model equipped with insulating panels. “Most new window ACs come with panels you place over the plastic adjustable side panels to boost efficiency,” says Chris Regan, CR’s senior test engineer for air conditioners. Adding weatherstripping around the perimeter will also prevent air from leaking in or out.
How We Test Window ACs
After installing the unit in a double-hung window in our testing chamber, we crank up the chamber’s heat to 90° F, then measure how long it takes the AC to cool the room by 10° F (the best units do it in less than 15 minutes). We also gauge how accurately the AC reaches the set temperature, whether each model can recover after a brownout, how intuitive the controls are, and how loud each unit is on the lowest and highest settings.
Below, grouped alphabetically by the size room they can cool, are some of CR’s top-performing window air conditioners. For more on getting the best fit, find out how to size a window air conditioner. You’ll find even more choices and a broader price range in our full air conditioner ratings and recommendations.

Amana AMAP061BW

CR’s take: The Amana AMAP061BW, a newcomer to our test labs, turns out to be a cool addition. It capably cools the test chamber and is a champ at recovering from brownout conditions when the voltage is low, earning an Excellent rating on that test. It comes equipped with a remote control, built-in timer, and dirty-filter indicator. But it’s a bit noisy on both low and high settings.

GE AHM05LW

CR’s take: A CR Best Buy, the GE AHM05LW earns a Very Good rating for comfort but, like the Amana, can be a bit noisy at any speed. It quickly recovers from brownout conditions and has a full suite of features, including a remote, built-in timer, and dirty-filter indicator.
Friedrich Kuhl SQO8N10D

CR’s take: The Friedrich Kuhl SQO8N10D makes an effort to blend in with your décor with a flat front instead of a grille. It aces the cooling test, earning an Excellent rating in that test, and runs quietly on low speeds, although gets a tad noisier on high. Controls are a cinch to use, and it’s equipped with all the conveniences of a timer, remote, and more. This 85-pound model comes with a slide-out chassis that makes it easier to install.
Kenmore 77080

CR’s take: With an Excellent rating for cooling—and intuitive controls—the Kenmore 77080 is a good bet for a midsized room. It’s pretty quiet on the lowest setting, but you’ll hear it running when you crank it up to high. At 52 pounds it weighs considerably less than the Friedrich above. It comes with a remote, built-in timer, and dirty-filter indicator.
LG LW1216ER

CR’s take: A CR Best Buy, the large, feature-filled LG LW1216ER has digital controls, and cooling is top-notch. It weighs 85 pounds, but its slide-out chassis makes it easy to install. It has all the convenience features—remote control, built-in timer, and dirty-filter indicator. It’s a good choice for a large living area and earns a Very Good rating for noise on low, which means it won’t annoy you if you’re watching TV.
SPT  WA-12FMS1

CR’s take: Another candidate for large spaces, the SPT WA-12FMS1 is top-notch at cooling, although it’s noisier than the LG at both low and high speeds. On the plus side, our testers found the controls were more intuitive; it earns a Very Good rating for ease of use. It also comes with a full range of features, including a remote, timer, and dirty-filter indicator.