HEPA Vacuum Enclosure Systems The Clayton Hepa Vacuum Enclosure Systems are based on our renowned HEPA Vacuum. This vacuum produces a high performance 220 c.f.m. airflow through our clear vacuum enclosures. The negative pressure inside the enclosure guarantees that no dust or other particles will escape the enclosure. All dust and particulate is filtered through the vacuum's three-stage filter system. The system filters out 99.999% of particles 0.12 micron or greater in size, which keeps your employees or students safe from harmful exposure.