Humidifiers

Using a humidifier can help ease dry skin and other problems associated with dry air. But choosing one involves trade-offs among efficiency, cost, noise, and convenience.

Who needs a humidifier? Anyone who suffers from uncomfortably dry or itchy eyes, throat, or skin, or whose asthma is a problem indoors during the heating season. Ideally, the indoor relative humidity should be 30 to 50 percent. But that level can drop significantly in winter, since cold air holds less moisture, and heating it makes it even dryer.

Humidifiers have improved over some earlier models, which spewed white dust in our tests. But that doesn't mean they all work equally well. What's more, Consumer Reports tests show that manufacturer claims can be a poor guide to how well a humidifier will work; several small tabletop models fell well short of their claimed output and may not raise the humidity to the desired level.


WHAT'S AVAILABLE



Major humidifier brands include Holmes, Honeywell, Hunter, Kaz, and Reli-On (Wal-Mart). Other brands include Bemis, Bionaire, Crane, Sears, Slant Fin, and Sunbeam.

Humidifiers come in three major configurations:

Tabletop. These cost the least and are fine for single rooms. Tabletop humidifiers include evaporative models, which use a fan to blow air over a wet wick, and warm-mist models, which use a heating unit to boil water before cooling the steam. However, smaller tanks need to be refilled more frequently. Evaporative models are noisy; warm-mist models are costly to run. Price range: $20 to $100.

Console. With larger tanks that require less refilling, console models are a suitable choice for humidifying multiple rooms. Console humidifiers are also efficient and can be placed unobtrusively. But all use evaporative technology and are relatively noisy. The larger the tank, the more difficult it will be to handle. Price range: $80 to $140.

In-duct. These whole-house humidifiers are convenient, quiet, and efficient, making them the least expensive to operate. Most are evaporative bypass units, which tap into the air supply and return ducts. Some are warm-mist; others are nebulizers, which use a spray technology. Using a nebulizer can result in "white dust." In-duct humidifiers can be used only with forced-air heat. While inexpensive to operate, they're the most expensive to buy and often require professional installation. Price range: $100 to $300, plus another $100 to $200 to install.


IMPORTANT FEATURES

A good portable model should offer relatively easy carrying, filling, cleaning, and wick replacement. Also look for easy-to-use controls and tanks that fit beneath faucets. Some portable models can be programmed to turn on automatically.


HOW TO CHOOSE



Decide the size you want based on how many rooms you need to humidify. Before buying a portable model, be sure you're willing to take the trouble to clean and disinfect it regularly to prevent mold and mildew. Otherwise, consider an in-duct humidifier, which is plumbed into the water supply and drainpipes, needn't be refilled, and has an easy-to-change filter that requires attention only once or twice a year.

Then keep these considerations in mind as you shop:

Be sure it has a humidistat. Whether it's dial or digital, a humidistat controls humidity levels and shuts the humidifier off when the set level is reached. Models without a humidistat can allow humidity levels to rise high enough to form condensation on windows and other cold surfaces. Overhumidification can also lead to mold and bacteria growth. Humidistats that display room humidity levels and settings are best.

Also be aware that some humidistats aren't accurate or reliable. And most portable humidifiers won't let you set humidity levels below 30 percent. When outside temperatures drop below 20° F, even a 30-percent indoor humidity level can lead to window condensation. Be sure to lower humidity levels as outdoor temperatures drop.

Noise level. Consider a warm-mist tabletop if quietness counts. All warm-mist humidifiers were quieter than evaporative models; some made little or no noise beyond mild boiling and hissing sounds. By contrast, comparably sized evaporative humidifiers generated 45 to 50 decibels on low settings--about as much noise as a small air conditioner--and emitted more than 50 decibels on high. At 80 decibels on its high setting, one model proved as raucous as a loud vacuum cleaner.

For larger areas, consider buying a noisier console model and locating it away from sleeping areas; the water vapor travels quickly through the home air and will still benefit remote bedrooms if doors remain open for air exchange. While you could alternatively buy several warm-mist tabletop models, doing so costs more.

Factor in the running costs. In-duct systems and other evaporative models deliver the most energy efficiency. While initially pricey, in-duct humidifiers are likely to cost the least over time; you can easily spend $350 per year to run four tabletop models compared with just $28 for one in-duct model.

Consider your water. Some humidifiers have lower output with hard water and require more frequent maintenance. Nonetheless, you'll find tabletop, console, evaporative, and warm-mist humidifiers that perform well under those conditions.