Humidifiers near you

EPA's fact sheet sorts home humidifiers two ways at once: by where they sit, and by how they turn water into vapor. The second distinction is the one that affects what ends up in the air.

The cleaning routine in EPA's fact sheet is more demanding than most owners realize, and it exists because standing water grows things. EPA advises emptying the tank, wiping all surfaces dry and refilling the water in portable humidifiers daily to reduce any growth of microorganisms, unplugging the unit first, and following the manufacturer's instructions for changing water in console humidifiers.

A deeper clean comes on a short cycle. EPA says to clean portable humidifiers every third day: empty the tank, use a brush or other scrubber to clean it, remove any scale, deposits or film that has formed on the sides of the tank or on interior surfaces, and wipe all surfaces dry, again with the unit unplugged. It advises following the manufacturer's suggestions on cleaning products or disinfectants and, in the absence of specific recommendations, cleaning all surfaces that contact water with a 3 percent solution of hydrogen peroxide, then rinsing the tank thoroughly with several changes of tap water so chemicals are not dispersed into the air during use.

Central and console units get the same principle in a different form. EPA directs owners to follow the manufacturer's directions for cleaning and maintaining console and central furnace-mounted humidifiers and, in particular, not to allow water to stand in a tank for extended periods and to keep the water clean. At the end of the season it advises cleaning the unit as directed, making sure all parts are dry before storage, disposing of used demineralization cartridges, cassettes or filters, storing the unit in a dry location, and cleaning it again and removing outside dust after storage.

The chalky film that settles on furniture near an ultrasonic humidifier is minerals from the water. EPA is measured about the health significance, stating that the federal government has not concluded that using tap water in ultrasonic or impeller humidifiers poses a serious health risk, while noting that researchers have documented that these humidifiers are very efficient at dispersing minerals in tap water into the air and that some consumers are bothered by white dust appearing on surfaces during use.

The stronger argument is mechanical. EPA states that minerals in tap water may increase the development of crusty deposits, or scale, in humidifiers, that scale can be a breeding ground for microorganisms, and that retarding the growth of scale is the most compelling reason to find alternatives to tap water. Its suggested alternatives are bottled water labeled distilled, which it describes as likely to contain lower mineral content than most tap water since distillation is the most effective method for removing minerals, or demineralization cartridges, cassettes or filters supplied or recommended for the humidifier.

EPA is careful about both options. It warns that not all bottled water is demineralized, since waters labeled spring, artesian or mineral have not been treated to remove mineral content, and that the ability of demineralization devices to remove minerals may vary widely, with further research needed on how well and how long they work. Its practical test is to watch for the appearance of white dust, which indicates that minerals are not being removed.

A central humidifier is a small plumbing and mechanical installation, not an appliance you set on a table. It is mounted on the supply or return plenum or ducted alongside it, fed from a water line with its own shutoff, wired for power and control, and given a drain where the design produces one. Because it introduces water into the air distribution system, the details that matter are the ones that keep water where it belongs: a reliable shutoff, a clean water connection, a drain that cannot back up, and a humidistat that actually governs the unit.

Control is where these installations most often disappoint. A humidistat set once in December and forgotten will keep making moisture through a warm spell or a cold snap, and the ceiling EPA sets is not a seasonal average but a limit. A control that responds to outdoor temperature, or simply an owner who checks a hygrometer and turns it down, is what keeps a whole-house unit from fogging the windows in January.

Ask three questions before buying. Where is the water connection and drain, and is either one in a place that would do damage if it failed. How is the unit cleaned, and can you reach the part that needs cleaning. And what happens to it in summer, since a humidifier left connected and un-serviced through the cooling season is a standing water source inside your ductwork. EPA's instruction to keep the water clean and not to let it stand for extended periods applies to central units as much as to portable ones.

Steam vaporizers boil water, and EPA's fact sheet says to keep them out of the reach of children because steam and boiling water may cause burns. That is the most direct physical hazard in this category and it is easy to design around: a warm mist unit in a child's bedroom belongs where a cord cannot be pulled and the unit cannot be reached.

The health caution is about who is most affected. EPA notes that the young, the elderly and people with lung diseases or respiratory allergies may be particularly susceptible to certain types of airborne pollutants, and that breathing mist containing microorganisms dispersed from a humidifier has been implicated as causing a certain type of inflammation of the lungs. It also acknowledges the state of the evidence honestly, saying that only limited information is available on the growth and dispersal of microorganisms and minerals by home humidifiers and that the possible health effects are not fully understood.

The instruction that follows from that uncertainty is simple and worth remembering: EPA advises stopping use of your humidifier and contacting your physician if you have respiratory symptoms you believe are associated with periods of humidifier use, even if you are following the maintenance directions. A humidifier is a comfort device, and it is not worth troubleshooting while someone in the house is unwell.

For a portable unit the purchase is the small number and the upkeep is the real one: distilled water or demineralization cartridges, replacement wicks or filters for evaporative models, and the time the three-day cleaning routine takes. For a whole-house unit installed on a forced-air system, the price is driven by the type of humidifier, how far the water line and drain have to be run and what they pass through, the electrical and control work, whether the plenum can take the unit without duct modification, and whether an annual service visit is included. Ask what the seasonal maintenance involves and who does it before comparing totals.

LokalMatch is where you start. You describe the situation once: how dry the house gets, whether windows fog, what heats the house, whether you want a whole-house unit or advice on portable ones, and where a water line could reach. HVAC pros serving your area receive that request and those interested contact you directly. Pros pay for the requests they receive, and homeowners use the service free of charge. LokalMatch does not install humidifiers, does not set prices, and does not vet, rank or recommend any company, so verifying licensing and settling the written scope remains with you.