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Air humidifier

Air humidifiers are used to eliminate the trouble caused by a low level of ambient humidity present in a residential, commercial or industrial environment. The drop of ambient humidity is generally caused by a hot air circulation drying the air, generally during winter, when the air heating period duration is extended, thus causing an important evaporation of water every day. Air humidifiers are important in controlling the environment in homes during very dry weather, or in winter whenever outside air of low temperature is drawn inside and heated, causing the relative humidity in the home to be lowered to an uncomfortable degree. Humidifiers associated with forced air heating systems can offset the decrease in relative humidity that occurs when cold air is heated in the winter months. Humidified air is healthier and a constant level of humidity throughout the season can reduce damage to wooden furniture and flooring caused by cycles of swelling and shrinkage. Humidified air can also reduce the build-up of static electrical charges. Self-contained room air humidifiers are used to introduce water, and other additives, to air in an enclosed environment, such as a room. Mist generators or mist sources, such as steam boilers, atomizers, nebulizers and ultrasonic vibrators, have been used to present water in the form of droplets to a passing flow of air. Steam generators comprise a water container and an electric heating element submerged in the water. Safety devices are provided for switching off the current as soon as the water level drops below the heating element. Porous medium humidifiers generally include a porous medium structure partly submerged in cold water contained in an open vessel and a blower unit drawing air through the porous medium structure. Ultra-sonic humidifiers generally comprise a container filled with water which is brought to a vibration by high-frequency vibrator means which causes the water to be atomized. An air stream directed onto the water surface carries the mist into the room to be humidified. The major drawback of both porous medium humidifiers and ultra-sonic humidifiers is that the water staying in the container is not heated to its boiling point as in the steam generator and, is therefore susceptible to the growth of micro-organisms. Warm-air humidifiers share the benefits of steam generators in that growth of micro-organisms is forestalled by heating the water to its boiling point. Warm-air humidifiers avoid the drawback of hot steam entering the room at a temperature to be selected by judiciously choosing the ratio of steam and air.

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