How to buy a humidifier
The right model might help alleviate some wintertime woes
Charming images of winter abound--a crackling, glowing fireplace providing warmth and comfort, rosy-cheeked kids skating on a frozen pond, a snowman standing guard on a snow-covered yard. But for many, winter and its arid air bring far-less attractive images--dry eyes, itchy skin, scratchy throats, and even exacerbated asthma problems. The colder weather means less moisture in the air, and heating this air in your home drives the relative humidity downward, making your home and your respiratory system feel dry.
Beyond a trip to the balmy tropics, one way to get some relief is with a humidifier. Choosing one of the three major types involves tradeoffs among several factors, including efficiency, noise, convenience, and cost. 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 might not raise the humidity to the desired level.
Tabletop. These portable models cost the least and are adequate for smaller spaces like an apartment or a single large room. Evaporative models use a fan to blow air over a wet wick, while warm-mist types employ a heating unit to boil water before cooling the steam in an air stream. You might need to refill the smaller tanks on tabletop models more frequently than with other models. Evaporative models are noisy because of the fan. Warm-mist models, because of the greater electrical consumption required to vaporize water, are more expensive to run. Price: $40 to $100.
Console. These floor-standing models have larger tanks that can provide longer operating periods between refills. Console models are a suitable choice if you want to cover multiple rooms or even an entire home with one unit, and are appropriate if your home does not use a central-fan-and-duct system to circulate heated air. These portable models (they are not installed) are also efficient, and their design, which features only a water reservoir, wicking media, and fan, allows you to put them wherever there is an electrical outlet in a common area of the home. The media absorbs water from the tank, the water is then evaporated by the fan's airflow, and that moisture will migrate throughout the home. On the downside, because they all use a fan, they're relatively noisy. Many models offer several speed settings, so you can set them to low speed for nighttime operation. Also remember that their cumbersome larger tanks can be more difficult to refill. Price: $80 to $140.
In-duct. These whole-house humidifiers are convenient, quiet, and efficient, making them the least expensive to operate. They are installed in your heating ductwork and are connected to your water supply and drainpipes, thus eliminating the need for refilling. Most are evaporative bypass units that tap into the air supply and return ducts of your forced-air heating system. Some are warm-mist, others are nebulizers, which use a spray technology. Some nebulizer models could generate tiny, solid-white particles from the minerals in the water. Evaporative models do not generate such dust. Maintenance usually involves the replacement of a filter-like wicking media or a spray nozzle once or twice a year. While inexpensive to operate, they cost the most initially and often require professional installation. Choose one with an outdoor-temperature sensor so that it reduces the amount of humidification as the outdoor temperature drops.
Price: $90 to $200, plus $100 to $150 for installation.
HOW TO CHOOSE
A portable model should be relatively easy to carry, fill, and clean. Also look for an easy-to-replace wick, simple controls, and a tank that will fit beneath faucets. Some portable models can be programmed to turn on automatically. All humidifiers require some effort to clean and disinfect regularly to prevent mold and mildew. An in-duct model is also the ideal choice if you plan to humidify the whole house and have a forced-air heating system. Then, after you determine the unit size you want based on the number of rooms you need to serve, keep these considerations in mind as you shop:
Size. Generally speaking, tabletops are the smallest and lightest models. But they are suited only for smaller spaces. Console models have a larger capacity--and thus a larger storage tank--to generate enough water vapor for a small house. (Remember, tank size is not as relevant as how much water it can evaporate in a given period of time and, more important, how much water is needed to be vaporized to attain the desired humidity level.) In-duct systems have automatic water-filling capability and require much less attention than portable models.
Humidistat. Whether a dial or digital type, 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 some humidistats aren't accurate or reliable. And most portable humidifiers won't let you set relative humidity levels below 30 percent. When outside temperatures drop below 20° F, even an indoor humidity level of 30 percent can lead to condensation on windows, doors or other cold surfaces. Be sure to lower the humidity level as outdoor temperatures drop.
Noise level. Consider a warm-mist tabletop if quietness counts. In our previous tests, 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 room 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 console model and placing it away from sleeping areas (remember, this type is noisier). The water vapor travels quickly through the air in your home and will still benefit remote bedrooms if doors remain open for air exchange. While you could alternatively buy several warm-mist tabletop models, that will cost more.
Operating costs. In-duct systems and other evaporative models deliver the most energy efficiency. You can easily spend $350 per year to run four tabletop models compared with about $30 for a single in-duct model.
Water supply. Some humidifiers produce a lower output with hard water. But you'll find tabletop, console, evaporative, and warm-mist humidifiers that perform well under those conditions. Hard water might create more maintenance to remove mineral-deposit buildup.
Consumer Reports recommends you clean portable humidifiers regularly to prevent mold growth, which can become an airborne allergen. Mold can grow in as little as 48 hours on wet surfaces. If you're not willing to make the effort to refill and clean your humidifiers, consider a permanently installed system (you still need to clean and maintain such a setup) or don't humidify--mold can pose much more of a health problem than low humidity.
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