In winter a typical addition to the morning routine includes slathering lotion on hands. Leaving the house with a stick of lip moisturizer is a must, too. Both are attempts to foil cracking skin and lips, by-products of the dryness brought on by winter. A simpler, long term solution would be installing a humidifier that benefits the entire living space by working with the existing system. Adding moisture inside the home helps relieve these minor physical grievances as well as improve breathing by hydrating sinuses. The walls, paintings, wood furniture, floors and instruments that can otherwise fissure at the seams from a lack of balanced air quality also stand to benefit from a whole house humidifier.
Acclimating the air in a home, be it using an air conditioner to draw moisture out to make rooms feel cooler in the summer or raising the temperature to combat chills in winter, is a numbers game. According to the Mayo Clinic a healthy relative humidity level inside the home is between 30 and 50 percent.
“Typically a whole house that is not humidified gets down to about 10 percent relative humidity in the winter,” said Jay Elepano, a senior product manager of Honeywell’s indoor air quality division. “That’s a northeast number.” Once the temperature outside drops to 30 degrees consistently, adding moisture back into the air can even help increase the comfort level inside without cranking up the furnace. Consider this: A house that’s 69 degrees with 19 percent relative humidity feels about 3 degrees colder than one with 35 percent humidity.
Nearly any home heated with forced air can be fitted with a whole house humidifier that uses the existing ductwork to carry warm, moist air into the living space. Whole house humidification typically falls into two categories, depending on how they impart moisture: Steam or evaporative. Steam, the newest and the most popular method of introducing humidity into northeast homes, according to Elepano, comes from a small, self-contained unit that heats water with electricity. The moisture-rich vapor that is created is carried into the ductwork by an insulated tube where the furnace’s fan pushes it through the home. Often the most expensive option, it has a much smaller footprint then the evaporative style and requires very little routine maintenance provided hard water isn’t being used. Less expensive, larger and more maintenance-heavy are evaporative-style humidifiers. Two of the more popular kinds, the drum and bypass, push water over a pad as the furnace’s hot air carries the vapor through the ducts. The furnace’s fan has to be on for the humidity to keep flowing; an evaporate humidifier with a built-in fan provides its own source of air making it more efficient to run.
Homes with baseboard heat have fewer humidifying options. The most common is a plug-in, tabletop version to condition a single room or small area. The cost is low but the amount of moisture dispensed is less than accurate. “There are larger evaporative models out that can sit in a closet and condition all the public space on the first floor and maybe the second floor of a house,” said Scott Ambrosio, president of Albertson-based Rebmann Plumbing, Heating and Air Conditioning.
Contractors install the more sophisticated whole house options though DIYers can tackle a basic drum-style evaporative humidifier in an afternoon.
It takes time to establish and maintain a home’s climate. After the initial set up, boosting the humidity to an optimal level may take up to a week of continuous operation, depending on the home’s size, how dry the season is and the amount of furniture in the rooms. Like the BTUs on an air conditioner, humidifiers are rated by how many gallons of water they emit per day. For example an area that is 500 square feet or smaller can be treated by a tabletop model that is rated at 1½ to 2 gallons per day while a home up to 2,000 square feet, which is just about the average size in the US, can effectively be treated by a whole house system pushing between 7 and 9 gallons per day. The more efficient steam systems can crank out up to 12 gallons per day for homes that are 3,000 square feet.
Some systems that use a pan of water to moisten the air can become a mold problem, as can any system that is left to run unsupervised. “One client called us when she retuned home and her walls were black with mold,” Ambrosio said. “She left the humidifier on while she was in Florida for three months.”