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Whole-House vs. Portable Humidifiers: Which Is Better?

By Kris Jensen-Van Heste

Q. What's the difference between a whole-house humidifier and a portable humidifier? Which is better?

A. A host of health issues can plague you if your house or room isn't properly humidified during the heating season. Severely dry air - a humidity level below 30 percent can cause respiratory irritation, uncomfortably dry nasal passages, nosebleeds and chapped and itchy skin, and it can also exacerbate conditions such as allergies and asthma.

Dry air also wicks moisture out of porous material such as wood including hardwood floors, and can cause splitting and cracking. Your home and its contents can benefit from careful humidifying, especially wooden musical pieces such as pianos, violins and cellos, antique furniture and even moldings and other woodwork.

Experts agree that a humidity level of 30 to 50 percent is optimal, and when you're running your heating system, that means running a humidifier, too. There are two basic types: a whole-house unit, typically connected to your furnace blower, and the portable or "room" unit.

Whole-House Humidifiers:

In general, a whole-house unit is an install-it-and-forget-it item. It's integrated into the blower system on your furnace, drawing water directly from your water supply. There are a few different types on the market, including a sprayer that injects mist into the airflow inside your ductwork and a foam cylinder that rotates in a water tray, with air blowing through and around it.

Pluses:

The whole-house system's greatest advantage is that it requires virtually no maintenance and keeps your entire home at a set humidity with just a one-time setup. Because it draws water from your plumbing system as it's needed, you never have to fill it or worry that it's not humidifying because it's run dry. It's virtually soundless, and initial cost is a fraction of what most portable units cost. In addition, most whole-house humidifiers literally cost pennies per year to operate.

Minuses:

Whole-house units are not as easy to bring home and use as a portable unit because some expertise is needed for installation, but just about any do-it-yourselfer can handle the job. They do tend to collect mineral deposits depending on the local water supply, and a whole-house unit warrants a thorough cleaning with diluted white vinegar at the end of the heating season before the deposits harden and become difficult to remove.

Portable Humidifiers:

Room units are freestanding machines, usually on wheels, that have their own water supplies and plug into standard electrical outlets. They're usually powerful enough to humidify one to two rooms, though larger units can provide enough humidity to keep several rooms comfortable. Small, desktop models are available, too, but don't expect a wide coverage area, just enough to keep you comfortable in your cubicle at work.

Pluses:

Portability is key here; convenience is also at the top of the list. You can move the unit anywhere you need it: a bedroom at night or a living area during the day. It's perfect for renters who can't install a whole-house unit, and when it's time to move, the humidifier goes, too. They're simple to operate and do a good job of keeping a smaller area humidified.

Minuses:

Better portable units are far more expensive than whole-house humidifiers: The whole-house units utilize your furnace blower, but portable units must include one. They're heavy, though most are fitted with rolling casters for ease of movement. Expect some noise too, sometimes as much as a window air conditioner. Maintenance is the biggest pitfall to the portable units; depending on the settings and how large an area you're covering, you may find you have to fill the water reservoir almost daily. Most units have removable tanks, but with others, you'll have to bring the water to the unit.

In addition, you'll want to keep the reservoir as clean as you can: Standing water is bacteria's playground, spewing germs into your indoor air. The Mayo Clinic recommends the following steps, for safe use of a portable humidifier:

  • Don't fill the humidifier with tap water; use distilled or demineralized water instead.
  • Empty the reservoir daily and fill it with fresh water.
  • Clean the unit thoroughly every three days.
  • Replace the filter at least as often as the manufacturer recommends.
  • Watch for dampness around the unit, which indicates that it's turned up too high and may be creating conditions for mold and bacteria to thrive.

Read More About Humidifiers

Before You Buy a Portable Room Humidifier
What's the Difference Between a Cool Mist & Warm Humidifier?
Video Buying Tips for Room Humidifier
Humidifier Care & Maintenance Tips
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