The Holmes Products HM3655-U humidifier pumps out up to 10 gallons of water into a dry home environment per day. That's about three times what other portable units we've examined can do in a day.

The maker claims it will cover 1,700 feet, making it a low-cost way to handle most houses. There is a drawback here though. To have a fan that's powerful enough to accomplish this, you will also have to put up with a fair amount of noise while it's on.

Filling any humidifier of this size is a chore and the HM3655-U is no exception. You'll probably have to do it in the bathtub. Fortunately, the unit's two tanks hold enough water to run for 24 hours of run time.

Microban, an antibacterial protection built into the unit's plastic construction materials, controls bacteria growth. It still is necessary, however, to wash the unit regularly. The wick-type carbon filters cost about $29.99 for a four-pack and will need to be changed frequently, especially if your water has a high mineral content.

Other appealing features of the Holmes Products HM3655-U include a programmable humidistat that lets you select the relative humidity you desire, a wick-type filter that collects minerals from the water before the water (and minerals) are released into the air, a filter monitor, and wheels for moving the unit.

Warranty
6 years