Air Filters for Ventilating Systems — Laboratory and in Situ Testing

Abstract

Over the past few decades, many laboratory test methods have been developed to measure and characterize air filters using different synthetic dusts. Today, with concern about indoor air quality (IAQ) and air pollution on the rise, new standards are being developed to test the ability of air filters to remove particles in the laboratory as well as in situ. Still, laboratory tests that use coarse dusts can give very misleading results, and the rated efficiency for a filter can decrease dramatically in real-world applications. For better understanding and prevention of IAQ problems, test methods should be extended to include particle shape, type, and properties.

References

ANSI/ASHRAE Standard 52.1-1992. “Gravimetric and Dust Spot Procedures for Testing Air Cleaning Devices Used in General Ventilation for Removing Particulate Matter,” American National Standards Institute, New York, 1992.

CEN EN 779, “Specifications for Particulate Air Filters for General Ventilation,” European Committee for Standardization (CEN), Brussels, Belgium, 1993.

Eurovent 4/9-1992, “Method of Testing Air Filters Used in General Ventilation for Determination of Fractional Efficiency.” Eurovent, Paris, revised 1996.

ASHRAE Standard 52.2 “Method of Testing General Ventilation Air-Cleaning devices for Removal Efficiency by Particle Size.” American Society of Heating, Refrigerating and Air-conditioning Engineers, Atlanta, June, 1999

Eurovent 4/10-1996. “Recommendation for in situ Determination of Fractional Efficiency of General Ventilation Filters,” Eurovent, Paris, 1996.

Lähtimäki

“Reliability of Electret Filters,” Indoor Air 93 Conference Proceedings, Helsinki University of Technology, Finland, 1993, Vol. 6, p. 463.

Lähtimäki

“Development of Test Methods for Electret Filters.” Report 320, Nordtest, Espoo, Finland, 1996.

STF 11 A95052, “Long-term Tests of Filters in Real Environment,” SINTEF, Trondheim, Norway, 1995.

Nordtest Method Nt VVS 117, “Electret Filters: Determination of the Electrostatic enhancement Factor of Filter Media,” Nordtest, Espoo, Finland, 1998.