A Little Moisture Does a Lot of Good for Comfort, Health

From Associated Press

Moisturizing the air in your home can help you feel more comfortable and breathe easier all winter long. But too much humidity can be harmful, especially if you have asthma or allergies. Here’s how to strike a balance:

Winter air is naturally dry, and once you turn on the furnace, the situation gets worse. These arid conditions irritate sensitive membranes in your nose and leave you more susceptible to assaults from viruses and allergens.

“Dry air triggers asthma and nasal congestion,” says Dr. Marshall Plaut, chief of the asthma and allergy branch at the National Institute of Allergy and Infectious Diseases, a part of the National Institutes of Health. If you suffer frequent winter colds or allergy attacks, low humidity may be the culprit.

Adding moisture to the air--experts favor 35% relative humidity--turns the tables on irritants. Humidification can help relieve your stuffy nose and itchy eyes, and it may ease asthma. Many people, including children, simply feel more comfortable with moisture in the air.

If you rarely suffer jolts of static electricity when you touch metal objects such as doorknobs, then the air in your home is probably humid enough.


For a more precise test, you’ll need a hygrometer. You can find these humidity measuring devices at most hardware stores for about $8. Humidity between 35% and 45%, but not more than 50%, is an acceptable range.

There are inexpensive ways to raise your home’s humidity--green plants and trays filled with pebbles and water, for example. But for most folks, the easiest and most effective route is a power humidifier.

Free-standing humidifiers moisturize a single room or a section of your home. Small, portable humidifiers are easy to truck from room to room. The larger console models humidify larger areas but are too heavy to move easily. Expect to pay anywhere from $100 for a portable unit to $1,000 or more for the largest consoles.

Central humidifiers attach to your heating system and offer whole-house moisturizing. These units draw their water from your plumbing system, so they don’t require constant refilling. Buying and installing a central humidifier will cost anywhere from $200 to $3,000 depending on the size of the unit needed for your home and the complexity of installation.

Ten years ago, doctors often recommended humidifiers to combat symptoms arising from dry air. Today, that advice is tempered by two areas of concern:

* Dust mites. Many people are allergic to the waste products of these tiny, insect-like creatures. “You can’t see them,” says Michael Kaliner, head of allergic disorders at NIAID, “but they are found wherever the temperature is more than 60 degrees F and the humidity is 50% or more.”

* Bacteria and mold. Humidifiers not properly maintained can become very efficient at producing and distributing illness-inducing organisms. Dirty water reservoirs and scaly, mineral-encrusted equipment offer an ideal environment for the growth of mold, mildew and other allergy-inducing fungi.

If you repeatedly have symptoms that mimic pneumonia or flu, your problems may be linked to the poorly maintained humidifier, say Dr. Harriet Burge of the Harvard School of Public Health.

All of the health problems associated with humidifiers can be prevented. Most important is to avoid over-humidifying your home. Room-size units rarely lead to excess humidity. Central units usually have controls to limit the amount of moisture they release. An occasional check with a hygrometer will ensure that your systems are adjusted properly.