ISO16890 air filter classification standard
ISO 16890 New Standard for Air Filter Classification (Classification of Air Conditioning Filters) The ISO 16890 standard differs from ASHRAE 52.2 and EN 779 in that its product class setting is determined by measuring and calculating the mass of particulate matter captured by the filter, known as the dust holding capacity. The particle size distribution state of the captured particles in the test is two typical distribution states set by the standard, which are called the standard urban atmospheric dust particle distribution state and the standard rural atmospheric dust particle distribution state. The distribution state is a bimodal curve of log-normal distribution. The two high points are located near the particle size of 0.3 μm and 10 μm, respectively. Both distributions are displayed by the relationship between particle size and its relative mass. The bimodal curve shown in the figure is typical. The small particle size curve mainly reflects the fine dust pollution caused by combustion (such as automobile exhaust, coal-fired power plants, etc.), and the large particle size particle curve mainly reflects the soil dust pollution caused by wind blowing. In simple terms, it is to use the standard given typical atmospheric dust distribution (two types in urban and rural areas), by using standard dust to conduct an efficiency test on the tested filter, to count the efficiency of each classification under a certain particle size and the corresponding particle size. The integrals in this distribution are weighted and averaged to calculate the filtration efficiency of standard atmospheric dust corresponding to this particle size. This method can well demonstrate the filtering effect of the filter in the real environment, and it is also easier for the public to understand.