Is CADR the most important indicator for air purifiers?

Edited by Charles.C 

                                                                               P1 retrieved from Deane,B

E11 level filter purification efficiency is 95%, and H12 level filter purification efficiency is 99.5%.Visually, it looks like H12 is better, but it is the same effect that air purifier recycle same space. Besides, the density of fliter is the higher volume.The amount of air per unit time filter require motor meeting high fan speed.Therefore,the air purifier would be noisier.

                                                                  P2 retrieved from Maomaozhe app

The CCM value of the filter represents the cumulative ability of the filter to purify pollutants. The higher the value is, the longer the life of the filter is. Generally speaking, the higher the CCM value is,and the higher the price is. The screen CCM value has two parameters, solid CCM value and gas CCM value.  

The solid pollutant CCM, excluding PM2.5 and other particles, is represented by ' P ', which can be divided into four levels, from low to high, namely P1, P2, P3 and P4. The total weight of the corresponding purified particles is 3,000 to 5,000 mg, 5,000 to 8,000 mg, 8,000 to 12,000 mg and above 12,000 mg, respectively.  

In addition to formaldehyde and other harmful gases, gaseous pollutant CCM is denoted by F, which can be divided into four grades, from low to high are F1, F2, F3 and F4. The total weight of purified formaldehyde is 300 to 600mg, 600 to 1000mg, 1000 to 1500mg and above 1500mg respectively, and the highest level is F4.  

                                                                             P3 retrieved from Cottonbro

Please it should be attention. In order to improve the CCM value of gaseous pollutants, some businesses will use carbon cloth, which is really strong in terms of purification efficiency, but will become acidic after a period of time. It is recommended to choose products with column-based activated carbon filter.  

In conclusion, the most important parameters of air purifier are  on these three.Although, noise does not need to pay too much attention to, the high-grade products on the market are large noise. Hence, the low-grade can be accepted.  

Here are two more tips.

1. Pay attention to the selection of air inlet and outlet location.Now the mainstream air machine design is from underneath wind out of upper wind, from side to upper wind, from side out of side wind .The first way of air duct design is the most reasonable, and high CADR value can be guaranteed without high power fan. The advantage of this is that the noise is relatively reduced, and can be placed at will. In case of side wind, it is also necessary to consider that there is no shelter around.
2. Don't pay attention to salesman who say they can filter at least 0.1 micronparticles. Because when particles are filtered, large particles are easily intercepted by the filter because of inertia;  The tiny particles will eventually be absorbed by the fiber because of Brownian motion;  The most difficult to filter are particles of medium size, known as the filter's most penetrable particle size, which is around 0.3 microns.

The filtering efficiency of the HEPA filter is mainly for the most easily penetrating particles, which are easily filtered regardless of size.

                                                                                P4 retrieved from Pixbaby

Reference:

Is CADR the most important indicator for air purifiers?. Maomaozhe app .N.D. Retrieved from : https://www.zhihu.com/question/26794287