Whole-House vs. Portable Humidifiers

Whole-House vs. Portable Humidifiers

The Spruce

Experts agree that a home humidity level between 30 and 50 percent is optimal. So if you're running your heating system, which can dry out the air, that generally means running a humidifier, too. There are two basic types of humidifiers: a whole-house unit that is typically connected to your furnace blower and a portable or room unit.


Whichever type of humidifier you use, make sure it's clean and maintained: A neglected humidifier can easily develop mold, mildew, and other unsightly (and even potentially unsafe) microbes.

Whole-House Humidifier Pros and Cons

In general, a whole-house humidifier is an install-it-and-forget-it appliance. It's integrated into the blower system on your furnace and draws water directly from your water supply. There are some different types, 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.

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

Some expertise is necessary to install a whole-house humidifier, but it is possible for a do-it-yourselfer if you've thoroughly read the product manual. Moreover, these humidifiers do tend to collect mineral deposits, so they can benefit from an annual cleaning with diluted white vinegar. Do so at the end of the heating season before the deposits harden and become difficult to remove.

Portable Humidifier Pros and Cons

Room units are freestanding humidifiers that have their own water supply and plug into standard electrical outlets. They're simple to operate. And they're usually powerful enough to humidify one to two rooms, though large units can provide enough humidity to keep several rooms comfortable. Small desktop models are available too, but don't expect a wide coverage area. They tend to cover just enough area to keep you comfortable in the space of something like a work cubicle.

Portability and convenience are the main perks of a room unit. You can move the unit anywhere you need it—a bedroom at night or a living area during the day. It's also perfect for renters who can't install a whole-house unit. And when it's time to move, the humidifier can easily be packed up and transported, too.

High-quality portable units are generally more expensive than whole-house humidifiers. The whole-house units utilize your furnace blower, but portable units must include their own. They also can be heavy, especially the powerful ones, 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 portable units. Depending on the settings and how large an area you're covering, you might find you have to fill the water reservoir almost daily. Most units have removable tanks for filling, but with others, you'll have to bring the water to the unit.

In addition, you must clean the unit often to make sure it stays sanitary. Standing water in a humidifier is bacteria's playground, and it will spew germs into your indoor air. The Mayo Clinic recommends the following steps to keep a portable humidifier clean:

  • 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 could indicate it is turned up too high or run too often.
Article Sources
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  1. How Dry Winter Air Can Cause Respiratory Problems - From Bronchitis to Nosebleeds. Cleveland Clinic.

  2. Humidifiers: Air moisture eases skin, breathing symptoms. The Mayo Clinic.