The most common humidifier models are evaporative and use evaporative humidifier filters. The filter is usually paper, cloth or foam that is saturated in water while a fan blows air through the filter or wick which forces moisture to evaporate into the air. This design is self regulating since dry air evaporates the water faster while higher humidity makes it harder for the water to evaporate. This is convenient because user control is not necessary and the level of humidity is self regulated.

The filter is used to trap particles and pollutants from the air so it works as an air filter as well as humidifier. Evaporative humidifiers come in all sizes from tabletop units to large house units that can work in conjunction with the home’s heating and cooling system.

Furnace Humidifier Filter

A furnace humidifier is any unit that is connected to the home furnace system and works with the heating and cooling system of the entire house. It uses the home’s water system to humidify the entire house and costs a little more than most units simply because of the size and its integration with the other systems in the house. A furnace humidifier filter uses the same evaporative design in which the air passes over a wet filter where moisture enters the air and particles are trapped. Aprilaire is the best brand for a furnace humidifier and is something that can be done as a home improvement project that will only take a day’s work.

Cool Mist Humidifier Filter

The cool mist humidifier is very common in small units and works by passing water through a wick or filter. It differentiates itself from other humidifiers in that there is no heating involved, hence the name cool mist. A vapor is pushed into the air with a fan and is considered a very safe humidifying technique for infants and small children.

In some climate specific areas where heating is not desired cool mist humidifiers are perfect. Since no energy is used for heating there is significant energy savings. Also, the droplets of water are larger than typical, cool mist humidifier filters don’t run the risk of white dust caused by the minerals in the water. While white dust is not dangerous it can be annoying when it settles on furniture and other things around the house.

Ultrasonic Humidifier

The key benefit of an ultrasonic humidifier is the energy savings. It also offers a very quiet humidification system because it uses a high-frequency vibration which releases micro-sized mist to moisten the air. There is very little maintenance on an ultrasonic humidifier which is where the cost savings come in. Humidifirst is the company that leads the pack in ultrasonic humidifier technology and its units can be used to produce cool or warm mist depending on the user’s desires. A setting control also allows for target humidity levels to be set and the unit stops when the target is reached. This is very useful to protect from over humidifying.