An absolute filter is a high-efficiency air filter that removes 99.97% or greater of airborne particles, including bacteria, viruses, and fine dust. These filters are commonly referred to as HEPA filters and are used in medical facilities, laboratories, and critical environments where contamination control is essential.
Technical Standards
Absolute filters must meet HEPA H13 or H14 classification under ASHRAE 52.2 standards, capturing particles as small as 0.3 microns. H13-rated filters achieve 99.95% efficiency, while H14 filters reach 99.995% efficiency. Pressure drop typically ranges from 0.5 to 1.5 in. w.c.
Applications
Absolute filters are specified for hospitals, cleanrooms, pharmaceutical production, and air purification systems. They protect patients and products from airborne pathogens and contaminants, making them critical in healthcare and manufacturing.
Operational Considerations
Absolute filters cost 50 to 300 dollars depending on size and classification. They require proper sealing to prevent air bypass and need replacement every 6 to 12 months. Systems using absolute filters must accommodate higher static pressure and airflow restrictions.