Cool Mist Humidifiers, Portable Humidifiers
Humidifier Features (continued)
Cool Mist Humidifiers.Cool mist humidifiers disperse cool moist air using one of three technologies: impeller, ultrasonic, or wick/evaporative. Impeller humidifiers, like several low-cost models sold under the Sunbeam and Vicks brand names, produce a cool fog created by a spinning disk that flings water onto a diffuser, which in turn breaks the water into small drops of mist.
Cool mist humidifiers have their pros and cons. On the plus side, these humidifiers are cheaper to run than warm mist humidifiers and the impeller and ultrasonic designs are extremely quiet; the fan on wick/evaporative humidifiers irritates some consumers but is considered soothing white noise by others. On the downside, the tank needs regular cleaning and refills because stagnant water is a breeding ground for bacteria that may wind up as mist in the air. In addition, impeller and ultrasonic humidifiers release minerals from the water into the air, so if your water is "hard" (i.e., it contains lots of minerals), consider using distilled water instead.
Portable Humidifiers vs. Home Humidifiers.In the humidifier world, size is indicated by the square footage the model can blanket with mist. Experts at Prevention.com note that small, portable humidifiers typically cover just one room (size varies by model) compared to high-priced central home humidifiers that are built into a home heating system and cover the entire house. Another indicator of size is the capacity of the water tank, or reservoir.
The best home humidifiers we found are the Vicks Warm Mist V745A, whose one-gallon tank handles areas of 1,000 to 1,200 square feet, and the cool mist impeller Honeywell HCM-630 QuietCare, which humidifies up to 1,050 square feet with a 1.5-gallon tank. The ultrasonic cool-mist Crane EE-5301 has a 0.9-gallon tank meant for up to 250 square feet, while the Holmes HM630-U Cool Mist Tower Humidifier simply claims to work in medium-sized rooms. How long these cheap humidifiers can run before needing a refill varies from the advertised maximum of 11 hours with the Crane EE-5301 up to 36 hours with the Holmes HM630-U. Note, however, that the duration between fill-ups depends on the temperature in the room, the desired level of humidity, the square footage, and the size of the tank; consumers often report needing to add water before the maximum run times have been reached.