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Hepa filter leaks....Help

Hepa filter leaks....Help

Hepa filter leaks....Help

(OP)
I have recenntly become involved in a Hepa filtration project and am having numerous "seal"failures when the units have been installed on site.  The filters are equipped with a gel seal and knife edge.  These however seem to be the source of the leaks.  New gel seals have been installed with improved but similar failures.  Are the other factors that can cause these gel seals to fail?  Just seaching for ideas as i am out of repair ideas and the manufacture is currently of little help.

RE: Hepa filter leaks....Help

I assume you've checked the operating airflow and it is within spec of both the filter and the air handler?

RE: Hepa filter leaks....Help

(OP)
Everything is right where it is supposed to be.  

RE: Hepa filter leaks....Help

Seems obvious - are the camming mechanisms applying adequate/equal pressure on the filter seal all the way around, and are you sure there is no bypass leakage in the sheet-metal enclosure/frame itself?

RE: Hepa filter leaks....Help

This is a serious situation that can lead to lawsuit. To limit your firm's liability you must be able to show documentation that you have reviewed the situation & that you hold the manufacturer or contractor at fault (per your finding) and you & the Owner will hold manufacturer or contractor or both strictly liable for any injury, liability, etc arrising from failure of the HEPA filters. Who is the manufacturer? I will keep away from them. The seal is the heart of the HEPA filter! The housing, seal & HEPA filter should be furnished by the manufacturer and quaranteed to be minimim 99.97% efficient. The manufacturer should inspect the installation & instruct the contractor & Owner how to install the filters. So if the seals don't work, chances are it is the fault of the manufacturer. Have your company lawyer write the manufacturer a letter.

RE: Hepa filter leaks....Help

Not sure if you have the ability to, but can you reduce your fan some?  Slight adjustments might mean all the difference with high pressure drop over the HEPA.  But again, be careful as this is not a permanent solution, it is one that can help you to see why the seals aren't holding, where, how long, and how else you might find a solution.  

RE: Hepa filter leaks....Help

If you have purchased decent quality filter/frames, then the units should have a seal test facility whereby you can apply a pressure across the filter to see if it is holding. We use TROX Ltd who are a German manufacturer although many companies have this facility.

Also, what is the pressure differential across the filter. Once you reach a certain value, i.e. 2" w.g. or 500Pa, you may find that the gel seal will be forced out anyway.

friar tuck of sherwood

RE: Hepa filter leaks....Help

(OP)
Thanx for the help everyone.  Our problem ended up being in the diffuser housing.  The biggest source of leaks tunred out to be spotwelds made during the construction of the housing.  Due to airflow paterns concentrations were occuring along the knife edge.  Once the spotwelds were properly sealed there have been no more problems.

RE: Hepa filter leaks....Help

Were the housings Krueger brand?

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