ATLANTA – A proposed addendum open for public comment is part of efforts to combine the American Society of Heating, Refrigerating and Air-Conditioning Engineers’ (ASHRAE’s) two standards on air filter testing. Combining Standards 52.1, Gravimetric and Dust Spot Procedures for Testing Air Cleaning Devices Used in General Ventilation for Removing Particulate Matter, and 52.2, Method of Testing General Ventilation Air-Cleaning Devices for Removal Efficiency by Particle Size, would have several benefits for users, according to Monroe Britt and James Hanley, chairs of the Standard 52.1 and 52.2 committees.

“One benefit would be having a single ASHRAE test standard for determining the filtration efficiency of HVAC filters,” noted Hanley. “This would reduce the number of tests needed on a filter. Currently, many filters are run twice, once for Standard 52.1 and once for Standard 52.2. It also would allow for one test rig to perform all the needed tests. Existing differences in the test rig requirements between the two standards make it difficult for one rig to serve both tests.”

Proposed addendum b would incorporate the Standard 52.1 sections on weight arrestance and dust-holding capacity into Standard 52.2 and delete some references to Standard 52.1 that occur in Standard 52.2. The addendum was open for public review until April 30. Also open for review is proposed addendum a, which revises the first dust-loading step, also known as the conditioning step, in Standard 52.2.

On a parallel path, the 52.1 committee is working to revise the 52.1 standard to remove the dust spot efficiency test requirements.

“Whereas this test method has served the air filter industry well for several decades, the particle size efficiency technology presented in 52.2 provides more direct and useful data than the dust spot efficiency data,” Britt said.

This revised Standard 52.1 will be submitted for public review in the fall of 2007. When approved, the 52.1 standard will become redundant and will no longer be needed.

Publication date:05/07/2007