According to the working principle, the humidifier is divided into electric heating, ultrasonic and wet film type. Wet film humidifier is also called the "purifying type humidifier", because it avoids the ultrasonic humidifier dioxide pollution problems, but also can reduce some of the air pollutants. The working principle of electric heating humidifier is to boil water and to produce water vapor. The working principle of the ultrasonic humidifier is that the water transformed into small droplets by ultrasonic oscillator, and then transform to spray by a small fan. Wet film humidifier working principle is same to hang clothes, artificially created a lot of air to blow big surface area of wet objects, which rises the humidity of the air. Wet film humidifier has the great advantages in energy saving and environmental protection, it has the trend of electric and ultrasonic humidifier, and so it is praised as "the third generation of humidifier"
Wet film humidifier is an isenthalpic humidification way, moisture evaporation are realized by absorbing the energy in the air, then air dry bulb temperature decreased, and the absolute water content in the air increased, but air enthalpy value remains unchanged.
Water flow evenly from the top of the wet membrane through the steam trap along the corrugated surface of the wet film to evenly moist the wet film from top to bottom, when dry hot air flows through the wet film surface, it will exchange the heat with the water in the wet film, water is heated and evaporated into vapor and flow into the air, which increase the humidity in the air, so that the dry hot air is transformed into the wet clean air.
wet membrane humidifier transports evenly the water to the top of the wet membrane by the water pump and distributor water, under the action of gravity, the water is downward penetrated along the wet film and come back to the main water tank to form a circulation. When the dry air passes through the wet film, the water fully absorbs the heat in the air to occur the vaporization and evaporation, so as to achieve the purpose of air humidification. In this process, the air humidity increases and the temperature drops, but the enthalpy is constant.
The filtered tap water (preferably pure water, softened water) enters the water tank, circulating water pump delivered the water to the water distributor at the top of the humidifier, the water is evenly distributed to high surface area of the evaporating material, the water is penetrated from the top of the evaporation material, and is absorpted by evaporation material to form a uniform water film, when the dry air is sucked into the humidifier by the draught fan, vaporization will occur due to a part of the water and dry air contact and absorb the heat to make the air moist (humidity increase), another part of the water will come back to the water tank, and can be used repeatedly through the circulating water pump .
