Humidifiers are generally used in the home and the working environment for the regulation of relative humidity. Humidity can be too high or too low and both situations have their attendant consequences. Thus, it is important to purchase the right humidifier that will set the humidity at an optimal level. Understanding the different types of humidifiers and how they operate is vital to achieving this aim.
Classification of Humidifiers
The most general classification of humidifiers is based on the type of air that is blown out of the humidifier. Thus, most humidifiers fall under two categories: warm air and cool air. Warm air humidifiers blow out warm moist air while cool air humidifiers blow out cool moist air. Humidifiers are also often classified according to the technology, area of coverage, and brand. The following are some of the more common types of humidifiers.
Evaporative Humidifier
This is the most common type of humidifier (cool air) and it consists of a very simple mechanism. Also known as Wick humidifier, the basic parts are a reservoir, a wick and a fan. The reservoir stores cold water which is dispensed into a base or basin. As the water is dispensed, the wick (which is a form of filter) absorbs the water while the fan blows air through it. The air evaporates the water and thus humidifies the air in the home. An evaporative humidifier is also self-regulating and adjusts itself to suit the prevailing humidity.
Impeller Humidifier
Also classified as a cool air humidifier, the impeller humidifier is similarly based on a simple mechanism. It consists of a disc and a diffuser. When powered, the disc rotates and its movement flings or throws water at the diffuser (which looks like a comb). The comb-like serrations separate the water into minute droplets which then float out into the air and are seen as a fog-like condensation coming out of the humidifier.
Steam Humidifier
Sometimes referred to as a vaporizer, the steam humidifier, a warm air humidifier, regulates the relative humidity by bringing water to boil and then releasing the steam into the environment. There are several advantages that make this type of humidifiers popular. For starters, they are cheap, discourage the spread of bacteria and molds and can also be used to alleviate cough by placing an inhalant in the unit or in front of the outlet.
Forced-Air Humidifier
This type of humidifier is used to regulate the relative humidity in the whole house, especially buildings that have a forced-air furnace. It has the distinct advantage of particularly protecting wooden furniture, wallpapers and wall paints from cracking and peeling. Forced-air humidifiers make use of bypass channels between the cold and heated air ducts and some of the common styles include: disc wheel, spray mist and bypass flow-through styles.
Ultrasonic Humidifier
Also classified as a cool air humidifier, an ultrasonic unit basically utilizes the sophisticated mechanism of piezo electrical transduction through the aid of a metallic diaphragm to form fine water droplets that are released into the room to regulate the relative humidity.
