The Steam humidifiers are the most economical humidifiers. The operation of this humidifier is simple. The machine uses electricity to a boil water and release steam into the air. Heat is easily increased or decreased depending on the room's current humidity. The released steam is sterile and free of minerals. To operate simply fill the base with water and plug the electrical cord into an outlet. Because the humidifier does not dispense minerals into the air, you can use tap water instead of distilled water. The use of tap water saves money. The most common use of a steam humidifier is to reduce coughs and cold symptoms. Medication may be added to the base water to soothe sore throats and tight chests. The steam also opens up nasal passages. Steam humidifiers are recommended for people suffering with respiratory illness or symptoms. Many parents use steam humidifiers to raise the humidity in nurseries or calm down children with symptoms of croup. Not only does a steam humidifier soothe respiratory problems, but also they kill germs in the air and release sterile water. Doctors often recommend people buy steam humidifiers when they have a history of respiratory illness. One important thing to remember is to keep steam humidifiers out of the reach of children. The steam is hot at the point of release and can easily burn a child. It is suggested these machines not be left in use unattended with children, however if they are located on a high shelf or dresser, there should be no problem. Although the steam humidifier costs less and saves money by using tap water, it does consume more electricity than spray or evaporative humidifiers. A steam humidifier that releases 350g of water can use up to 325 watts of electricity. The evaporative would use about 10 watts. To assure your steam humidifier lasts, perform routine maintenance on it. A few times a year be sure to empty the base and clean out the limescale deposit. The build up, much like that in a kettle, is not hard to clean. Simply add a small amount of limescale removing powder to some water and let it sit for the suggested time. Empty, rinse and it is ready to use again. Be sure to empty all water out of the base when the humidifier is not in use. If excess water sits it may become stagnate and full of bacteria.