Classification and working principle of humidifiers.According to different humidification principles, humidifiers on the market can be divided into two types: ultrasonic oscillation type and water molecule evaporation type. The latter is divided into thermal evaporation type and cold evaporation type due to different evaporation methods. Thermal evaporation is easy to understand, and the principle is exactly the same as when we boil water with a kettle. When the water boils, a large amount of water vapor will be generated and evaporated into the air. The disadvantages of this method are also obvious, that is, it cannot be dry-burned, the risk factor is relatively high, and it has been gradually eliminated by the market. Therefore, there are only two common humidifiers on the market: ultrasonic humidifiers and cold evaporation humidifiers.

1. Ultrasonic humidifiers
The so-called ultrasonic humidifier uses the high-frequency oscillation of ultrasound to break water into ultrafine particles of about 1μm to 5μm and release them into the air to achieve the purpose of humidification. Almost all the relatively cheap small humidifiers we see in daily life are cool-mist humidifier.

2. Cold evaporation humidifiers
The principle of cold evaporation humidifiers is also very simple, which is to simulate the evaporation of water in rivers, lakes and seas in nature to create a humidification effect. The speed of natural evaporation must be very slow. Either increase the surface area of the container or increase the efficiency of evaporation. As a small household appliance, it is unlikely to increase the evaporation area, so we have to increase the efficiency of evaporation. We have just passed the heating method, so there is another common way, which is to use a fan. The cold evaporative humidifier uses a fan to continuously accelerate the evaporation of water on the surface of the water-absorbing material to achieve the humidification effect.

What are the standards for choosing a cool-mist humidifier? Humidification capacity is a very important indicator. However, users often overlook it when purchasing, and are generally attracted by the water tank volume that the manufacturer emphasizes. In fact, increasing the volume of the water tank is the least costly. The humidification capacity can truly determine whether the humidifier you choose is suitable for you. The calculation of humidification capacity is also a relatively complicated matter, which requires consideration of indoor and outdoor temperatures, current air humidity, room area, floor height and other factors. If the humidifier is not cleaned for a long time, it will breed bacteria. These bacteria will affect our health when entering the air with water vapor. So when choosing a humidifier, it is best to choose a humidifier with sterilization capabilities.