How to Improve Your Indoor Air Quality
A guide to getting the most out of the machines that make your home comfortable: air conditioners, air filters, and humidifiers.
How clean and comfortable is the air inside your home? Is it too dry? Too hot? Too dusty? You spend the majority of your life indoors, so it's worth it to pay attention to the quality of air in your home, notes Jay Portnoy, MD, chief of Allergy, Asthma, and Immunology at Children's Mercy Hospital in Kansas City, Missouri.
There are so many machines available today for the sole purpose of helping us breathe easier indoors. But simply having an air filter doesn't mean your home air quality is perfect. Mold, dust, and other allergens can accumulate in your air conditioner, humidifier, and air filter to make the air you're breathing more polluted than ever. Here's what you need to know to keep these devices clean, efficient, and effective. (Note: In desert regions, mold is not an issue because of the already-low humidity.)
What they do: As anyone who lives in a hot-weather climate knows, air-conditioning is a must-have summertime comfort. But did you know that air conditioners do double-duty by cooling the air and also removing moisture so you feel less hot and sticky?
How to use them effectively: To cool down the entire house, central air-conditioning is usually the most effective way to go. Be aware, though, that a central air conditioner that's too powerful for the size of the house will cool the air down quickly, but won't have a chance to remove moisture from the air adequately if that's a concern. If you just want to cool a single room, a less-expensive option is a window-mounted air conditioner (probably too expensive too operate, though, in desert regions).
Safety alert: Because water condenses on an air conditioner's cooling coils, they can be a potential source of mold, Dr. Portnoy notes.
Upkeep tips: Whether you have central air-conditioning or a window unit, air conditioners should be serviced at the beginning of each season by a heating, ventilation, and air-conditioning professional who can clean the coils and make sure they're not contaminated.
What they do: Air filters remove irritants like mold spores, pet dander, candle and cigarette soot, and even skin cells from the air, making it easier to breathe, especially for people who have allergies.
How to use them effectively: High-efficiency particulate air (HEPA) filters generally cost more than ionic filters, but HEPA filters are more efficient at removing all of the airborne particles, says Dr. Portnoy. The best way to filter air for the whole house is with a filter that's placed in the furnace, he says. (In desert regions, the filter may be attached to the air conditioner as part of an electric heat pump.) Be sure to leave the system's fan running even if the heat is not on to allow the filter to do its job.
Safety alert: "Some air filters produce ozone," Dr. Portnoy says. "The ozone oxidizes the chemicals that produce smells and makes the air smell fresh, but doesn't remove them." Because ozone itself can be an irritant, he recommends steering clear of ozone-producing devices (most are labeled on the package).
Upkeep tips: Over time, HEPA filters clog up and need replacing. How often you need to change them will depend on how contaminated the air is. Electrostatic filters should be cleaned according to the manufacturer's directions (some have parts that can be hosed off or wiped down, while others use disposable filters).
Additional advice: Don't bet on your air filter to protect you from mold allergens. "Where there's water, there's going to be mold," Dr. Portnoy says. The best remedy is to get rid of the source of the mold (such as a leak or damaged drywall) and use a diluted bleach solution to remove the mold spores.
What they do: Does walking on your carpet give you an electric shock? Those sparks are an indicator that the humidity level in your home is too low. A humidifier can counteract this by adding moisture to the air.
How to use them effectively: Most people rely on stand-alone humidifiers to add moisture in individual rooms, which is fine if you can't attach a unit to the furnace. However, according to Dr. Portnoy, the most effective way to humidify the whole house is usually with an evaporative model that can be placed in your central furnace. To give the humidifier enough time to work effectively, you may need to leave the fan running even when the heat is off.
Safety alert: Stand-alone cool-mist humidifiers "can shoot bacteria and mold into the air," Dr. Portnoy says. Be sure to follow the manufacturer instructions for cleaning. Hot humidifiers, or vaporizers, avoid this problem, but can be a scalding risk around toddlers, who may accidentally tip them over.
Upkeep tips: A diluted bleach solution is the best way to clean cool-mist and cool-evaporative humidifiers. For more information, refer to the manufacturer's instructions.
Additional advice: The optimal humidity level is between 35 and 50 percent -- any higher, and you'll end up creating a breeding ground for mold and bacteria, Dr. Portnoy notes. A simple way to measure indoor humidity levels is with a hygrometer (humidity meter), which can be purchased inexpensively at a drugstore.
Originally published on BHG.com, March 2005.