As far as the types of humidifiers go, as far as the "portable" or stand-alone models are concerned, there are generally two options: Cool Mist or Warm Mist. Now there are other types, but these are the most popular, and rather than list the hundreds of possible variations, I'm going to talk about the simple humidifiers available at places like Wal-mart and various department stores.
First, a basic understanding of how each type works.... Obviously, each puts moisture into the air, but they use different methods of doing so.
Cool Mist humidifiers have a water tank which must be filled with water. If the water tank is
allowed to run dry, the humidifier will stay running, but no humidity will be added to the air. Water passes
through the unit (usually a tray at the bottom) to a separate compartment with a "wick" which absorbs the
water. This wick is a large mesh-like material which has a lot of surface area, and is extremely absorbent. I have
included a picture here, taken from the kaz.com website.
Above the wick is a fan which pulls air past the wick. Because of the large surface area of the wick (which is saturated with water), quite a bit of moisture is pulled from the wick into the air, where it is then blown by the fan into the room. Since this moisture is typically room temperature or slightly cooler, these humidifiers are defined as "cool mist".
Warm Mist humidifiers come in a few varieties. Some have a basin, some have a tank. All are filled with water and use heat (a heating element) to make the water evaporate into the air. If they run out of water, most of the newer ones shut off automatically. Many have a "medicine cup" where liquid medication designed for humidifiers can be added. The warm mist passes by this compartment and helps bring it into the air along with the mist. Warm mist humidifiers used to be dangerous to toddlers, because they would get extremely hot (especially if allowed to run out of water), and they were also dangerous when tipped. Most are much safer now, and will shut off automatically when tipped or when out of water, preventing the scalding-hot temperatures of their predecessors.
Features to look for
Pros and Cons
|Warm Mist||Cool Mist|
Really, neither type is a whole lot "better" than the other, and only you can choose which type is best in your situation. If the humidifier is going to be placed in a child's room, and you're still unsure, ask your doctor which he/she recommends and why. Your doctor can make a recommendation based on safety issues as well as bacterial factors that may come into play.
Disclaimer: All information on this page is to be taken as opinion and not as fact. I disclaim all liability for anything that happens to anybody as a result of this existence of this page, any other pages on this site, or any other companies, people, places, or pages, that have been mentioned, referred to or linked to. Use this information at your own risk.