By: Nancy Zimmerman, Senior Research Scientist, Kimberly-Clark Professional |
The Kimberly-Clark Professional Filtration team traveled from our home base in the South to cold, snowy New York City in mid-January to attend the ASHRAE 2014 Winter Conference. Our primary goal was to participate in several important technical committee meetings focused on air filtration.
52.2 Debate Continues
The committee meeting for ASHRAE Standard 52.2 was one of the more contentious meetings we’ve attended to-date. Here, a very vocal and aggressive debate centered on whether or not to adopt the standard’s Appendix J as a formal part of the standard.
For those unfamiliar with Appendix J, it’s important to note that when ASHRAE updated Standard 52.2 in 2007, it included an Appendix not found in the previous standard: Appendix J: Optional Method of Conditioning a Filter Using fine KCL Particles. The Appendix was created to mollify critics of ASHRAE 52.2, who were concerned that air filters featuring an electret charge performed at high filtration efficiencies during initial testing while their filtration efficiencies could decline during actual use. Thus, they argued, the resulting MERV of the filter (as indicated by that initial test) would not represent the true minimum filtration efficiency of the filter.
The critics’ solution was to “level the playing field” by masking an electret filter’s charge. The MERV-A test described in Appendix J subjects the filters to extreme loads of very fine particles – many times more than[MR1] what the filter would be exposed to in the real world. The test was designed only to drive down the efficiency of electret filters. It represents a “worst-case” scenario that is likely to never happen.
This is one of the reasons the electret masking step was not added to the 52.2 Standard as a mandatory part of the test but was included as an option only. We believe it should remain optional, especially given the clear benefits of electret-treated media filters in capturing the submicron particles that can cause health problems.
GPC 35P: Air Filters & Energy Consumption
GPC 35P is a proposed guideline to establish a consistent methodology to determine the energy consumption caused by air-cleaning and filtration devices. While the stated goal of this new committee focuses on energy consumption, much of this committee meeting was spent discussing the test dust to be used. The logic here is: let’s design the test the right way from the very beginning.
We support efforts to create a test dust that is more representative of real-world conditions and look forward to participating more in this committee.
We also had an opportunity to visit the co-located AHR Expo, which featured the latest products and technologies on display from more than 1,900 exhibiting companies from around the world. There were many hardware and equipment vendors showcasing their wares at the Expo, but relatively[MR2] few companies promoting IAQ specifically.
Question: When evaluating and selecting air filters, do you look primarily at a filter’s MERV or do you check the ability of the filter to remove submicron particles – a measurement not indicated by a filter’s MERV? Let us know and tell us why in the comments section.