If you want to get technical, you can measure the humidity level in your home with a hygrometer.
But I don’t need one to tell me the humidity in my house is way too low. The floorboards have contracted, leaving wide gaps between them. The wainscoting in the family room has shrunk so much I can see the ugly old color it used to be peeking through at the seams. Heck, even the tomatoes I put on the kitchen windowsill a few days ago are starting to look sun-dried. I don’t think there’s an ounce of moisture left in anything around here.
This always happens in winter. The temperatures drop, the heat comes on, and the home humidity level takes a nosedive. Low humidity not only does a number on wood and vegetables left on the windowsill, it can also increase static electricity, make wallpaper more likely to peel, and can contribute to physical ills like dry skin, dry throat, dry lips and nosebleeds.
But none of that has to happen. Moisture can be added to the air with the use of a home humidifier.
Home humidifiers come in three types: tabletop, console and whole-house units, which attach directly to a forced-air heating system.
Tabletop and console models are portable. The former are designed to humidify a single room, the latter, larger spaces.
Deciding what kind
Shopping for a portable humidifier can be confusing, because there are lots of choices.
-- Ultrasonic models create a cool mist by means of ultrasonic sound vibrations.
-- Evaporative models add moisture to the air by way of a fan, which blows air over a wet wick, belt or filter.
-- Steam humidifiers (also called vaporizers) create steam by boiling water with an electric heating unit.
-- Impeller models produce cool mist using a high-speed rotating disc that breaks the water into fine droplets.
Each type can do the job, but each also has its cons:
-- The fan on evaporative models can be noisy.
-- Humidifiers that emit hot steam can be unsafe around children, and the boiling water can leave hard-to-clean mineral deposits stuck on the unit.
-- According to the Environmental Protection Agency, impeller and ultrasonic models are the most likely to disperse microorganisms into the air, as well as “white dust” created from dissolved minerals in tap water.
The downside to all portable humidifiers is that they need to be refilled with water frequently, and cleaned on a regular basis. If they’re not kept clean, bacteria and fungi can grow in the water tank and could be released in the mist. Breathing in fungi-filled air could cause lung problems.
To reduce the possibility of that happening, the Consumer Product Safety Commission recommends these precautions:
-- Change the water in your humidifier daily.
-- Use distilled or de-mineralized water in your humidifier, to reduce scale build-up and the release of “white dust.”
-- Clean your humidifier well and often during the heating season and replace filters or belts when needed.
-- Drain and clean the unit’s tank before you store it away for the summer, and clean it again after summer storage.
There are chemical additives, antibacterial filters and demineralization cartridges available for use in humidifiers; they reportedly provide varied benefits, including: prevention of calcium and lime scale build-up, deterring of mold and bacterial growth, and prevention of the release of minerals into the air. Some models are made with antibacterial plastic; others use ultraviolet light to deter bacterial growth.
Deciding what size
The output of portable humidifiers is measured by the number of gallons of moisture they can add to the air per day. Tabletop models range in output from one gallon to four gallons per day, estimates Ken Carpenter, manager of Burnt Hills Hardware. The cost, at his store, ranges from $24.99 to about $59.
“Three gallons would probably do five [hundred] or 600 square feet, and that’s easily two good sized rooms,” he said. Some three-gallon models for sale on the Internet advertise an output that covers up to 1,500 square feet.
The console humidifiers sold at Burnt Hills Hardware range in output from eight to 12 gallons per day and range in price from about $100 up to $150. Larger models that release 14 gallons of moisture per day are available elsewhere.
Most 12-gallon models for sale online advertise up to 2,500 square feet of coverage, whereas 14-gallon models generally are said to cover 2,900.
Deciding on features
When shopping for a portable humidifier, it’s important to consider not only the size of the area you need to humidify, but the features that will make that job easier. Some popular portable humidifier features include:
-- Digital humidistats. These allow you to set the humidity level with more precision than you can with dial-controlled humidistats.
-- Multiple water tanks. The more water the humidifier can hold, the less frequently you’ll need to refill it.
-- Lift-out water tanks. These save you the trouble of having to lug the whole unit to the sink when it’s time to refill it, but make sure they will fit under your faucet, and won’t be too heavy to carry, once full.
-- Wheels. If the console unit can roll, it’s much more portable.
Whole-house humidifiers cost a bit more than the portable type, and should be installed by a professional, but once they’re in, they require little baby-sitting. Prices range from $300 to $500 installed, depending on the model, says John Batease, service manager for Buhrmaster Energy Group in Scotia. Installation takes a little more than an hour, he estimates, and the units can be installed on a new or pre-existing furnace.
Whole-house humidification systems are plumbed into the home’s water supply and send moisture through the air ducts. There are three common types to choose from: Drum system, flow-through or spray mist.
Drum system has a drum, covered in a foam or fabric belt, that rotates through a water reservoir. Air from the heating system passes over the damp drum pad, picks up the moisture, and distributes it throughout the house.
In the flow-through system, water drips onto a foam or aluminum pad. Heated air flows through the pad and picks up the moisture. Excess moisture drains away.
And in the spray mist system, an electronic mister sprays water vapor into the air.
Batease favors the flow-through system. “The water actually passes through and it’s not sitting there stagnant; that can create mold,” he explained.
Humidistats for whole-house humidifiers are installed either on the ductwork or upstairs in the home. “Sometimes you can attach them to an outdoor sensor and they regulate themselves according to the humidity outside as well,” Batease noted.
Once they’re up and running, you can pretty much forget about a whole-house humidifier and it will still do its job, for a year. For it to continue working properly, it should be serviced annually.
“Normally, if a contractor is there inspecting your furnace, there’s no charge for checking your humidifier,” Batease said. The filters, he notes, must be cleaned once a year. “If you have hard water, sometimes they can gum up a little,” he cautioned.
Newer systems, he says, are quite reliable. “The old ones had floats in them and stuff that could get clogged up and [cause the reservoir to] overfill,” he said.
According to research by Consumer Reports, whole-house humidifiers are more efficient to run than portable models. The organization reports that it costs about $30 per year to operate a whole-house humidifier, compared to as much as $350 or more to humidify a home with four tabletop models.
No matter which type of humidifier you decide to use, it’s important to maintain a healthy humidity level in the home.
The U.S. Consumer Product Safety Commission recommends maintaining a relative humidity level somewhere between 30 percent and 50 percent.
You can check the humidity level with a hygrometer, which you can find at a hardware store. But even without one, if there’s too much humidity, you’ll know it, says Batease.
“You start seeing mold in your house, you know you’ve over-humidified; or your windows are all wet all the time, you’ve over-humidified.”
And if there’s too little humidity in your home, that’s easy to tell too — just look for shrunken woodwork or prematurely aged tomatoes on the windowsill.