Idea about filters

Filters are used to purify and filter conditioned air before it reaches people. Types include mesh, pocket, and carbon filters, as well as HEPA filters-the latter being commonly used in hospitals.

Classification of filters according to codes:

Standards

ASHRAE 52.2 - This standard covers the general testing of removal efficiency by particle size.

EN 779:2012 - This standard widely used in Europe defines the filtration classes according to the average filtration efficiency of particles with a diameter of 0.4 micron size.

EN 16890 - This new standard defines the air concentrations of particles whose diameters are less than 10, 2.5 & 1 micron size.

EN 1822:2009 - This standard covers HEPA filtration