[labnetwork] HEPA Filters

[Weaver, John R]

In my experience, the major reason for changing HEPA or ULPA filters - unless there is an "incident" - is the failure of the seal between the T-bar ceiling grid and the filter housing. If you are using a gel-track system, this is generally a non-issue.

The only warning is that if you are using a closed cell (or worse, open cell) gasket material and it fails, you may not catch the failure with a particle counter. The particles given off and allowed through are often far bigger than a particle counter can detect. A bright-light inspection is the primary method for finding these large particles. You need to get on a ladder and inspect the top of the T-bar downstream of the seal. The other approach is to pull a filter module and inspect the gasket directly. Unless there is chemical usage in the area, the gaskets should "dry out" at about the same rate. Most neoprene seals (closed cell) should last more than 15 years; I've had some last more than 20.

John

John R. Weaver
Facility Manager
Birck Nanotechnology Center
Purdue University
(765) 494-5494
jrweaver at purdue.edu

From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Flückiger Philippe
Sent: Tuesday, September 25, 2012 4:22 AM
To: Dennis Grimard; labnetwork at mtl.mit.edu
Subject: Re: [labnetwork] HEPA Filters

Dear Denis,

Let me mention that EPFL is running with the original HEPA filters since 14 years (1998) and still reach the class 100 specifications.
EPFL has no plan to change the HEPA filters. Only some pre-filters might be occasionally changed for example after construction work in the area.

Anyway, back to your question facilities would pay for this.

With my very best regards,
Philippe

Dr Philippe Flückiger
Director of Operations
http://cmi.epfl.ch/
Phone +41 21 693 6695

De : labnetwork-bounces at mtl.mit.edu<mailto:labnetwork-bounces at mtl.mit.edu> [mailto:labnetwork-bounces at mtl.mit.edu] De la part de Dennis Grimard
Envoyé : vendredi 21 septembre 2012 00:17
À : labnetwork at mtl.mit.edu<mailto:labnetwork at mtl.mit.edu>
Objet : [labnetwork] HEPA Filters

All:

Do any of you have to pay for the replacement of your HEPA filters in your cleanrooms?

Thanks ...

--
Dennis S Grimard, Ph.D
Managing Director, Lurie Nanofabrication Facility

University of Michigan
1246D EECS Building
1301 Beal Avenue
Ann Arbor, MI 48109-2122
(734) 368-7172 (Cell)
(734) 647-1781 (Fax)
http://www.lnf.umich.edu

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