The function of the fresh air system is in addition to ventilation and air exchange,
Its most important function is to filter pollutants from the air.
Therefore, fresh air
The filter screen of the system is integrated
The most important link in the system
According to the level, principle, and material, the filter types of the fresh air system can be divided as follows
The filter screen of the general fresh air system can be divided into three levels, namely initial efficiency filter screen, medium efficiency filter screen, and high-efficiency filter screen.
1. Primary filter screen: Filter outdoor large particles of dust and insects.
2. Medium efficiency filter: Filter small particulate matter such as outdoor pollen.
3. Efficient filter screen: HEPA filter screen, which can filter the vast majority of dust above 0.3 microns
In the fresh air system, the primary, medium, and high efficiency filter screens are not used separately, but rather two or three types of combined use, equipped with two or more types of fresh air systems that pass through the screen to achieve better performance. Currently, the most common filtration principles are divided into two types: physical filtration method and electrostatic filtration method.
1. Physical filtration: Filter materials are commonly used in different levels from G1 to H13. The higher the level, the greater the wind resistance, the more thorough the filtration, and the more expensive the price.
2. Electrostatic dust collection: PM25 has excellent over consumption effect and low wind resistance, and there is no need to replace the over consumption screen with frequent alarms. The disadvantage is that it produces ozone when it does not swim, and when ozone reaches a certain level, it is harmful to the body. Therefore, electrostatic dust collection must have strict requirements for the production of ozone
Choose products that meet national standards and pass quality standards.
At present, the most commonly used method in fresh air systems is the physical overflow method. The overflow network needs to be replaced regularly, otherwise it cannot achieve good overflow effect. The electrostatic dust collection method is in the popularization stage, and some large companies have developed or are currently developing related functions. It is expected that in the next few years
Various filtering methods will be widely used.