What is a Cool Mist Humidifier?

A cool mist humidifier replenishes moisture in the air without any risk of scalds or burns. Three types of a cool mist humidifier are available: evaporation, impeller and ultrasound. When manufacturer instructions are followed, these machines can safely humidify indoor areas, but if they are not cleaned properly, they provide a breeding ground for molds and other allergens.

When the air is especially dry, it will draw moisture from any available source, including furniture and people. Wood might become brittle, and cracks might form, causing permanent damage. People might notice that skin, lips, throat and nasal passages feel dry and tight. Hair becomes brittle and prone to frizz and split ends. Dry air also produces static, and electronic devices might suffer.

Vaporizers and warm mist humidifiers can address this issue, but they replenish humidity using steam, making them potential sources of burns. Parents of small children and owners of pets might be especially concerned about this risk. A cool mist humidifier offers a method of restoring moisture to the atmosphere without any danger of scalding.

One of the most common types of cool mist humidifier relies on evaporation to add moisture to the air. Water is drawn up from a reservoir by a wick. A small fan blows across the wick, evaporating the water and humidifying the air. Only water evaporates, meaning that ordinary tap water can be used, and any mineral deposits remain on the wick.

An impeller cool mist humidifier relies on a spinning disk to get moisture into the air. A small electric motor drives the impeller, which splashes water onto a diffuser. Water emerges from this diffuser in the form of microscopic droplets, small enough to be suspended in the air and humidify the room. Impeller humidifiers are not silent, but the motor makes less noise than the evaporation humidifier’s fan.

Ultrasound humidifiers work much like conventional sound speakers, vibrating a diaphragm at high frequency to break down the water into microscopic droplets. As the name implies, the vibrations are outside of the range of human hearing, so these machines are entirely silent. They typically are more portable than other types of humidifiers and often are more efficient as well. For these reasons, they typically are more expensive.

Although warm mist humidifiers can potentially cause burns, they produce enough heat to sterilize their mist. A cool mist humidifier does not have this advantage, making regular cleaning and maintenance especially important. Without proper maintenance, microorganisms might use the humidifier as a breeding ground, and spores or other allergens might be dispersed along with the moisture. The owner’s manual should include instructions for proper cleaning and maintenance.