There are two types of pre-filters: mesh and carbon. A mesh pre-filter only traps solid particles. A carbon filter traps both solid particles and gaseous pollutants. The type of pre-filter used in an air purifier will depend on the other types of internal filters.
Description
Specification
The prefilter traps large particles such as dust, oil, and carbon (from the compressor), and pipescale and rust (from the pipework) and thus protects the sterilizing filter and increases its lifetime.