Particle size for greatest penetration of HEPA filters - and their true efficiency

Technical Report · Wed Dec 01 04:00:00 EST 1982

DOI:https://doi.org/10.2172/6241348· OSTI ID:6241348

da Roza, R A

The particle size that most greatly penetrates a filter is a function of filter media construction, aerosol density, and air velocity. In this paper the published results of several experiments are compared with a modern filtration theory that predicts single-fiber efficiency and the particle size of maximum penetration. For high-efficiency particulate air (HEPA) filters used under design conditions this size is calculated to be 0.21 ..mu..m diam. This is in good agreement with the experimental data. The penetration at 0.21 ..mu..m is calculated to be seven times greater than at the 0.3 ..mu..m used for testing HEPA filters. Several mechanisms by which filters may have a lower efficiency in use than when tested are discussed.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6241348
• Report Number(s): UCRL-53311; ON: DE83008439
• Country of Publication: United States
• Language: English

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54 ENVIRONMENTAL SCIENCES
AEROSOLS
AIR POLLUTION
AIR POLLUTION CONTROL
COLLOIDS
COMPARATIVE EVALUATIONS
CONTROL
DENSITY
DISPERSIONS
DOCUMENT TYPES
EFFICIENCY
FILTERS
FILTRATION
PARTICLE SIZE
PHYSICAL PROPERTIES
POLLUTION
POLLUTION CONTROL
RADIOACTIVE AEROSOLS
REVIEWS
SEPARATION PROCESSES
SIZE
SOLS
VELOCITY