Searching for relief from dry, itchy eyes, nose, throat and skin, or just for a way to calm winter-enhanced asthma? Those are the reasons most people seek out humidifiers when the thermometer dips low. Adding moisture to dry air can also help alleviate the pesky byproducts of winter heating, such as static electricity, peeling wallpaper and cracks in furniture and paint.
Striking a fine humidity balance
Relative indoor humidity should be between 30 and 50 percent, although the ideal level is lower than 30 when outdoor air is colder. The percentage refers to the amount of moisture air can contain before it's completely saturated. At 50 percent, air is holding half of what it potentially can. Warmer air can hold more moisture, meaning that as the temperature rises, relative humidity falls, and the air looks to any source - including you, your family and your furniture - to gain moisture. Cold outdoor weather combined with indoor heating can cause a 10 percent drop in humidity levels, leading to uncomfortable conditions.
Of course, too much moisture isn't good, either. It encourages biological organisms like dust mites to make your home their own. Anything above 50 percent (or less if outdoor air is below 20 F) can promote the growth of mold and bacteria, meaning a humidistat to control moisture levels is not only a good idea but should be considered a necessity if you plan to get a lot of use out of the humidifier.
The good thing about humidity is that it makes air feel warmer than it actually is, allowing you to turn the thermostat down a few degrees and stay comfortable. That fact gives many brands bragging rights, so look at other points as well.
Area to be covered
Depending on the amount of space that needs to be humidified, different styles will prove better fits. With portable, console, or whole-home models, coverage is one of the most important factors in how to choose a humidifier.
Be prepared to keep it clean
If you can't commit to cleaning and disinfecting them, most humidifiers won't be for you. You're better off looking for in duct humidifiers because mold and mildew released into the air by poorly maintained humidifiers can cause more problems than dryness. Some better humidifiers employ demineralization cartridges, antibacterial filters, ultraviolet (UV) light or other sanitizing methods.