HEPA & ULPA

HEPA is short for High Efficiency Particulate Air. ULPA is Ultra Low Particulate Air. Each are designed to trap small airborne particles and contaminants. HEPA have minimum efficiency of 99.97% at 0.3 microns. ULPA are 99.999% at 0.12 microns or higher. However, if you take air flow and other variables into account, HEPA are cheaper, have a lower resistance to air flow, and usually have a longer service life than ULPA filters.