Humidifier for one. Make that to go

Humidifiers can be useful appliances, particularly as the weather turns colder and heaters dry out the air. Used occasionally, they can also be soothing for people with colds or upper respiratory infections that dry out the sinuses or throat. As described in ConsumerSearch's full report on humidifiers, most models are designed to be used in large spaces like a bedroom or family room.

That said, if you need something for a very small space like an office cubicle, or if you're a frequent traveler and want something you can easily pack, these humidifiers are too big for the job. In that case, you might want to consider two mini cool-mist humidifiers, both of which are about the size of a squat hardcover book and use plastic water bottles (like you'd find in any convenience store) instead of a reservoir: the Air-O-Swiss 7146 Travel Ultrasonic Humidifier (*Est. $50) and the Sunpentown SU-1051 Mini-Humidifier (*Est. $50).

But if you're shopping for the best humidifier that money can buy, are either of these models worth it?

Both mini humidifier units are fairly similar. They come with 110/240-volt travel adapters so they can be used at home or overseas, and each has a two-level adjustable output. The Sunpentown also comes with a blue night light (more on that later), while the Air-O-Swiss boasts a replaceable silver ion filter to fight microbial growth. The Sunpentown is slightly heavier than the Air-O-Swiss (2 pounds vs. 1.3 pounds), but neither is what you'd call hefty.

We found more consumer reviews for the Sunpentown humidifier than we did the Air-O-Swiss, but neither model is included in the major reviews we consulted for our full report on humidifiers. At Amazon.com, nearly two dozen owners weigh in on the Sunpentown SU-1051, giving it an average rating of about 4.5 stars out of five. All but a couple of these reviews are overwhelmingly positive; both owners lodging serious complaints say that the unit broke down fairly quickly. About the worst thing thing most owners can say beyond that is that the humidifier's blue night light it too bright. Otherwise, it's ideal for travel or for a nightstand, and owners like the fact that they can use bottled water instead of having to fill a reservoir. We also found a couple of user reviews at Walmart.com, both of which are positive.

The Air-O-Swiss receives only a handful of user reviews at Amazon.com, but they're equally positive. What's interesting is that one reviewer says he's taken Air-O-Swiss humidifiers to the ends of the earth -- literally. Scott Mosher of Morrison, Colo., loves this little unit and says he used the humidifier at McMurdo Station, the American research station in Antarctica, where "the average humidity is in the single digits." He is particularly pleased with its output, which "puts out less water than my full-size Air-O-Swiss unit at home, but a remarkable amount for a unit this size." We also found a review at Achoo Allergy and Air Products, an online retailer, which cautions users to place the humidifier on a stable surface, since it can easily be knocked over when the water bottle is attached.

Given the positive consumer feedback, we'd say both humidifiers are worth considering if you're a frequent traveler. But if you're looking for a humidifier that'll stay put in a room -- even a small one -- you're probably better off considering a larger unit like the Honeywell HCM-630 humidifier (*Est. $50), which ConsumerSearch names the best warm-mist humidifier, or the WindChamer HUNi humidifier (*Est. $35), a ConsumerSearch runner-up.