If dry winter air is making your home uncomfortable, you have two basic options. You can buy a portable humidifier for the rooms where you notice it most, or you can have a whole-home humidifier installed on your furnace. Both add moisture. They differ in how much of the house they cover, how much work they take, and how well they control humidity during a Minnesota winter.
How each type works
The EPA groups home humidifiers into three kinds: portable units, larger console units that sit on the floor, and central units built into the heating and cooling system. See the EPA guide to use and care of home humidifiers.
Portable humidifiers sit in a room and treat the air near them. Common types include ultrasonic, impeller (cool mist), evaporative and steam vaporizer models.
Whole-home humidifiers mount on the furnace or ductwork and add moisture to the air your furnace sends to every room. According to Carrier's overview of whole-house humidifier types, there are three main designs:
- Bypass: uses the furnace blower to push air through a water panel.
- Fan-powered: has its own fan to move air through the water panel.
- Steam: electrically heats water to make steam and can run apart from the furnace heating cycle.
Side-by-side comparison
- Coverage: A portable unit treats one room or a small area. A whole-home unit treats every room your ductwork reaches.
- Water supply: You fill a portable unit by hand. A whole-home unit connects to your water line.
- Daily work: The EPA advises emptying, drying and refilling portable units daily, and scrubbing them every third day. Whole-home units need service on the manufacturer's schedule, usually a water panel replacement at least once a season.
- Control: Most portable units have a simple dial or built-in humidistat. A whole-home unit can use an automatic control with an outdoor temperature sensor that lowers humidity as it gets colder outside.
- Noise and space: Portable units take up floor or table space and make some noise in the room. A whole-home unit sits in the mechanical room.
- Upfront cost: A portable unit has a low purchase price and no installation. A whole-home unit requires professional installation.
Water quality and cleaning
The EPA's humidifier guidance raises two concerns that matter for this decision:
- Minerals: Ultrasonic and impeller units release minerals from tap water into the air. You may see this as white dust on furniture. The EPA suggests using distilled water in these units.
- Microorganisms: Standing water in any tank can grow bacteria and mold, which the unit can then spread into the air. The EPA links breathing this mist to a type of lung inflammation and says young children, older adults and people with lung disease or allergies may be more sensitive.
A portable unit only stays safe if you keep up with daily emptying and regular scrubbing. A whole-home evaporative unit has no tank of standing water for you to manage, but its water panel collects minerals and needs to be replaced on schedule.
Cost factors to weigh
Total cost depends on more than the purchase price:
- Number of rooms: Covering a whole house with portable units means buying, filling and cleaning several of them.
- Ongoing supplies: Portable units may need distilled water, filters or demineralization cartridges. Whole-home units need replacement water panels.
- Installation: A whole-home unit needs a water line, a drain for most models, wiring to the furnace, and a control. Steam models also need electrical service.
- Your furnace: Your furnace and ductwork must have room and the right setup for the humidifier you choose.
Which one fits your home?
A portable humidifier may be enough if:
- You only need moisture in one bedroom or a small apartment.
- You rent or do not have a forced-air furnace.
- You are willing to clean it every few days through the whole season.
A whole-home humidifier usually makes more sense if:
- You notice dry air throughout the house, not in one room.
- You have a forced-air furnace and plan to stay in the home.
- You do not want to fill and clean tanks all winter.
- You want automatic control that helps limit window condensation on very cold nights.
Steps you can take now
- Buy a hygrometer and measure humidity in several rooms for a week.
- Note whether dry-air symptoms show up in one room or throughout the house.
- If you already use a portable unit, check it for scale, film or a musty smell, and clean it following the manufacturer's directions.
- Check your windows on cold mornings. If they are wet, you need less humidity, not more.
When to call a professional
Call for an assessment if you want whole-home humidity, if your existing furnace humidifier is leaking or not adding moisture, or if you are not sure your furnace can support one. A technician can check your furnace, ductwork, water supply and drain, and recommend a bypass, fan-powered or steam model that fits. Learn more about whole-home humidifier installation at Krinkie's. If you are also planning a furnace replacement, that is a practical time to add a humidifier.
Common questions
Can one portable humidifier handle a whole house?
Usually not. A portable unit treats the room it sits in or a small area, so covering a whole house often takes several units.
How often does a whole-home humidifier need maintenance?
Most evaporative models need the water panel replaced at least once a heating season, and some models more often. Follow the manufacturer's schedule for your model.
Do I need a forced-air furnace for a whole-home humidifier?
Yes. Whole-home humidifiers mount on the furnace or ductwork and use the duct system to spread moisture through the house.