If you're asking yourself the question, Do I need a humidifier? The answer most likely is no. Humidifiers typically don't improve overall health, nor are they needed for the health of your home. If they did, people and homes in dry climates would be less healthy than those in humid climates, and this is simply not the case. But that is not to say that a humidifier won't make you more comfortable. Humidifiers also can help relieve some symptoms related to colds and even some respiratory conditions, but the use of a humidifier in these cases should be discussed with your doctor.
Symptoms of Low Humidity
Dry air leads to dry skin, itchy eyes, and irritated nasal passages. It can cause a bloody nose or an itchy throat and can aggravate symptoms of the common cold and some respiratory ailments. It also increases static electricity, which you feel in your clothes and hair and on furniture and carpeting. Raising the humidity usually reduces or alleviates these symptoms if you can get it up to a comfortable level while raising it a marginal amount may have no effect on your comfort.
Measuring Humidity Levels
Humidity is the amount of water vapor in the air. The humidity we talk about in our homes is called relative humidity and is expressed as a percentage. It is typically measured with a simple device called a hygrometer. The standard recommended range for comfort and air quality is between 30 and 50 percent. Humidity lower than 30 percent may be uncomfortably dry, while levels higher than 50 percent can promote bacterial and mold growth and other problems in the home.
You can pick up a hygrometer at a hardware store or home center and use it to measure the humidity of any area of your house. With a hygrometer and some experimentation, you'll be able to maintain desired humidity levels without over-humidifying.
Options for Adding Humidity
Humidifiers come in several different types and a range of capacities. Small humidifiers, such as vaporizers and old-fashioned impeller humidifiers, are best for small spaces and limited use, such as humidifying a room overnight for a sick person. Vaporizers typically produce steam, which is cooled before being blown into the air. Cool-mist humidifiers often use ultrasonic mechanisms to create a cool mist of vapor. Humidifiers for large areas include evaporators, which blow air through a water-soaked pad, and whole-house humidifiers that inject water vapor into the ductwork of a forced-air heating system.
Considerations for Wood in the Home
It's a law of nature that wood expands and contracts with changes in humidity. If you really can't bear the sight of gaps in wood flooring or creaky floorboards in the wintertime, you probably should choose a different flooring material. Maintaining a high level of humidity throughout the dry season is simply not feasible, and it wastes a lot of electricity. In terms of construction materials, if wood parts spent some time in your climate (and in your house) before they were installed, chances are they'll be sufficiently acclimatized to withstand seasonal humidity changes without significant cracking and shrinkage. It's when you import woods directly from humid areas into dry environments that you most likely run into trouble.
Wood musical instruments present a dilemma: if you start humidifying them, you might have to keep humidifying them for the life of the instruments (at least during dry periods). This also means you can't forget to maintain the humidification system at all times. On the other hand, if your violin or guitar makes it through the winter without humidification—and without cracking—chances are it will survive the dryness every year. For this reason, many musicians in dry climates choose not to humidify their instruments directly. Adding moderate general humidity to a home shouldn't affect a wood instrument either way.