What are humidifiers?

Humidifiers are devices that release water vapor or steam. They boost the amount of moisture in the air, also called humidity. Types of humidifiers include:

• Central humidifiers. These are built into home heating and air conditioning systems. They're meant to humidify the whole house.
• Ultrasonic humidifiers. These devices use sound waves to release a cool mist.
• Impeller humidifiers. These humidifiers give off a cool mist with a rotating disk.
• Evaporators. These devices use a fan to blow air through a wet wick, filter or belt.
• Steam vaporizers. These use electricity to create steam that cools before leaving the machine. Don't buy this type of humidifier if you have children. The hot water inside a steam vaporizer may cause burns if spilled.

Humidifiers only add moisture to the air. You can't use them to breathe in products such as essential oils for aromatherapy.