HEPA in an ERV – Beyond MERV 16?
alexdorf
| Posted in Mechanicals on
While I’m sure we can get into the semantics of whether a building even needs this level of filtration – I’m just curious about the options out there, especially when clients start doing their own research and ask “what about HEPA?”
Are there any ERVS that will work with a HEPA filter? or a MERV 16?
Follow up, do these filters present too much restriction in air flow?
Cheers,
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Replies
You can for sure use much higher levels of filtration for HRV/ERV. To reduce restriction you need to use external filter boxes, and look at 2" to 4" filters. This chart demonstrates the hit you'd take on your static pressure/flow using a 16x16x2 Merv 11 prefilter + 16x16x2 HEPA filter ducted at 6".
https://www.hvacquick.com/products/residential/Indoor-Air-Quality/Inline-Filter-Boxes/HVACQuick-CFB-HP-Series-HEPA-Inline-Filter-Box
You can achieve much lower pressure drops by using filter boxes that host larger (like 24x24x2) filters arranged in a 2-4 filter array.
Thank you for sharing, exactly the info I was looking for!
No worries :-) I just installed the 6" MERV 13 version of that box and measured minimal pressure drop (less than .1 W.C) across it at around 90 CFM using a 14x14x4 filter.