In order to achieve these levels you can use a simple fan filter unit which comprises of a pre filter (G filter) and a final filter (EPA, HEPA or ULPA). Or, if you are also controlling temperature and humidity, you would use a HVAC system in which you would have a pre-filter (G filter), a fine-filter (M or an F filter) and a final filter (EPA, HEPA or ULPA).
A pre-filter captures coarse dust. A fine-filter captures particles measuring 0.2- 3 micron and a final filter removes air born particulate; that is those particles measuring 0.1 -0.3 micron.
The classification of the filters are calculated according to how efficient the filter media is at removing the stated particle size.
There are quite a few options in each category but here at Clean Environments we use a G4 pre filter and a H14 final filter as standard.