Air purifiers two hard targets necessary: ??1, must ensure that the indoor air reaches a certain number of ventilators, air purifier which brand is good, which requires a built-in fan air purifier has a certain amount of wind. To ensure that international standards are: for an area where five air changes per hour. 2, an air purifier must first purification efficiency is relatively high removal efficiency (CADR) The higher, the better the show air purifier purification efficiency (CADR) values ??are three indicators: 1, the solid particulate matter, also known as the Dust (Particle), Typically used to simulate domestic cigarettes, air purifiers price, also known as soot 2, volatile organic compounds (VOC), commonly used as a test source 3 toluene, formaldehyde (Formaldehyde) due to the general effects of air purifiers for dust is very obvious place , while the effect of volatile organic compounds and formaldehyde place of dust is not as good, Chaozhou air purifiers, so many businesses marked only dust CADR. The main air purifier on the market performance, advantages and disadvantages, and adapted to control air pollutants. Consumers should understand the types of air pollutants own home environment, air purifiers rankings, and refer to Table 2 describes, after purification purposes, economic strength, and the purchase price, replacement cost, electricity to run a comprehensive assessment and secondary pollution Make sure to select what type of air purifier. Some businesses on the market is called "cold catalyst", "complex type" principle air purifier, purifying effect which has not been confirmed by the international mainstream science, the actual effect is the lack of scientific testing proved.