How do HEPA and ULPA filters differ in a fan filter unit for clean room applications?

Selecting between HEPA and ULPA filters for clean room fan filter units hinges on your cleanroom's requirements. HEPA filters, commonly used, capture 99.97% of particles at 0.3 micrometers, making them ideal for less rigorous settings like ISO 7 or ISO 8 cleanrooms. Conversely, ULPA filters, which are pricier, remove 99.99% of particles as small as 0.12 micrometers, suiting stricter environments like ISO 5 or above, often needed in industries such as pharmaceuticals or semiconductors. For general purposes, HEPA filters are adequate, but ULPA filters are critical for highly controlled spaces.