Nowadays, air purifiers and fresh air systems have become one of the many items purchased by many families. When considering the purchase of air purifiers or fresh air systems, people hope to purify indoor air. Indoor air pollutants are mainly PM2.5, etc. Suspended particulate matter, volatile organic pollutants, and microorganisms such as bacteria.
At present, the mainstream filtration technology of air purifiers on the market is mechanical and electrostatic. Mechanical type is passive adsorption filtration, which draws indoor air into the air purifier through the exhaust fan, and then completes the particulate matter through the filter inside the machine. Filtration of volatile organic matter. The electrostatic type uses a high-voltage electrostatic field to form a corona. The free electrons and particles collide with the dust particles, causing the particles to carry a charge and being adsorbed by the filter under the action of the electric field force.
Common filter screens mainly include HEPA filters and activated carbon filters. The HEPA filters are made of multi-component glass fibers, which can efficiently capture particles in the air and effectively filter out inhalable particles, smoke, bacteria, etc. above 0.3 microns. The activated carbon filter utilizes the unique pore structure of activated carbon and the wide pore size distribution to adsorb organic pollutants in the air.
In addition, some air purifiers use silver ion purification, negative ion purification, water washing, photocatalyst and other technologies, making the air purifier market appear full of flowers.
How does the fresh air system work? The fresh air system is an independent air treatment system consisting of a ventilation system and an exhaust system. The basic principle and function is to discharge the indoor air while exhausting the indoor air, so that it can be opened without opening the window. Ventilation and ventilation effect. If the air conditioning system is equipped with an electrostatic dust box or filter, it will have air purification function. In addition, the fresh air system will be equipped with a heat exchanger to have heat exchange function.
Careful friends can easily find that the role of the air purifier is to clean the existing air in the room, while the fresh air system realizes indoor and outdoor air circulation through the exhaust and air supply ducts, and at the same time purifies the air that is sent in, and realizes full heat exchange. The fresh air system is also an air purifier. If the filter is used to purify the air, the filter screen needs to be replaced regularly. If the replacement is not timely, the risk of secondary pollution will occur.
Therefore, if only from the principle of air purification, the air purifier and the fresh air system are the same, whether it is HEPA filter, activated carbon filter, electrostatic dust collection, silver ion purification, negative ion purification, are based on the following principles First, using the principle of inertial collision adsorption, after the change of the direction of airflow, the contaminated particles will move linearly under the influence of inertia, and then adsorbed by the filter material. Second, diffusion adsorption, which is carried out by using Brownian motion. An adsorption, the particles from the gas flow to the surface of the fiber, under the influence of static factors, directly adsorbed by the fiber, have a better effect on the filtered gas; third, direct adsorption, the adsorption of the substance larger than the filter medium in the particle is intercepted, The smaller the pore size, the higher the adsorption efficiency, and the better the particle removal rate.
Since the fresh air system and the air purifier use the same air purification technology, can the two completely replace each other?
The air purifier purifies the existing air in the room, causing people to feel bored when the air purifier is turned on for a long time. At this time, the window ventilation will make the outdoor air pollutants enter the room without any obstacles, which is obviously not feasible. The fresh air system can achieve indoor and outdoor air circulation without opening the window, thus reducing the feeling of boredom. Although some fresh air systems have the function of purifying air, in the case of extremely serious air pollution, the filtering capacity of the fresh air system is insufficient. The indoor air is still not clean enough. If the filtration capacity of the fresh air system is strengthened, the amount of air sent into the room may be reduced, and the air pressure difference between the indoor and outdoor areas will occur. The outdoor polluted air will enter the room through the gap between the door and window.
Although the fresh air system and the air purifier use the same technology for purifying the air, the core functions of the two are different. In addition, whether the introduction of outdoor air to achieve ventilation is the main difference between the two, which makes the fresh air system and Air purifiers can't completely replace each other, only the two complement each other, can maximize the indoor air cleaning, so that people can breathe.