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3rd Tuesday SC Chapter Meeting

Topic: "Filter Performance Over Time: Efficacy and Efficiency"

About the Speaker:

Kathleen Owen

Kathleen Owen, Owen Air Filtration Consulting, is an air filter/cleaner filtration efficiency and test method development expert. She worked on the ASHRAE and EPA projects that developed ASHRAE air cleaner efficiency test methods 52.2 (for particles), 145.2 (gases), and 185.1 (UV-bioaerosol). She also developed chamber test methods for gases and bioaerosols based, in large part, on the AHAM CADR test method.  She was the first chair of ASHRAE committee SSPC 145 and is the current chair of ASHRAE 52.2.  She is also the research subcommittee chair for TC2.3 Gaseous Contaminants and is a member of SSPC 185, TC2.4, TC2.9, TC2.3 and of the US TAG to ISO 142. During her 33 years at RTI Intl., she ran ASHRAE 1360-RP and worked on many ASHRAE and EPA projects on air cleaning and air quality including the recent EPA EIP on air cleanup in VI situations.  She ran the RTI commercial air cleaner test lab for 20 years.  Her BS in chemical engineering is from NCSU, and her MS in Air Pollution Control Engineering is from UNC-Chapel Hill.

The nature of dust collected on HVAC air filters and how filter performance changes over time were investigated in a two-study project. In-situ use data were compared to American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) 52.2 test results and to expected use patterns to determine if the standard test and expected use were reasonable. Separately, dust collected on used filters was examined for size and composition and compared based on type of use.

This project resulted in an extensive database of the properties of HVAC filter dust and changes in filter performance.  Filter efficiency as it changes over time is not well represented by the dust loading steps in ASHRAE 52.2.  Appendix J conditioning was needed to bracket the minimum in-situ efficiency of the charged media filter.  Also, filters did not reach final efficiency levels as high as those obtained in the 52.2 test.  Efficiency reporting values calculated from the minimum efficiency curve are more relevant to in-situ performance than the use of average or final dust-loaded values.

Also, standard service lives were too short; filters are not likely to reach the pressure drop recommendations. This means savings in either filter purchases or predicted energy use based on likely pressure drop.  There was a clear distinction between collected dust from commercial and residential sites: commercial collected mainly aluminosilicates; whereas, residential had mainly dander.  The SEM analysis showed dust particles from ~3–200 µm.  And, as expected, dust on HVAC filters does not match ASHRAE dust for chemical composition. 

Directions to meeting:

Still Hopes Directions
Tuesday, November 20, 2018, 5:30 PM until 7:30 PM
Still Hopes
1 Still Hopes Dr
West Columbia, SC  29169
Michael Rushing
Registration is recommended
No Fee
No Fee
No Fee