About This Archive  | DCHAS-L 2020 Index   | DCHAS-L Yearly Index
person wearing a disposable face shield and surgical style mask

Check out Safety Emporium for your N95, N99, and face shield needs.

Previous by Date:
Subject: [DCHAS-L] ASHRAE guidance on Reopening Schools and Universities
Date: Tuesday, July 7, 2020 at 8:28:27 AM
Author: "Stuart, Ralph" <Ralph.Stuart**At_Symbol_Here**KEENE.EDU> 		Next by Date:
Subject: Re: [DCHAS-L] ASHRAE guidance on Reopening Schools and Universities
Date: Tue, 7 Jul 2020 10:20:07 -0400
Author: Margaret Rakas

From: Monona Rossol <0000030664c37427-dmarc-request**At_Symbol_Here**LISTS.PRINCETON.EDU>
Subject: Re: [DCHAS-L] ASHRAE guidance on Reopening Schools and Universities
Date: Tue, 7 Jul 2020 14:07:36 +0000
Reply-To: Monona Rossol <actsnyc**At_Symbol_Here**cs.com>
Message-ID: 2119826668.2976700.1594130856983**At_Symbol_Here**mail.yahoo.com
In-Reply-To


All good advice except the MERV 13 filter recommendation.  A study now shows the bug goes through a properly installed MERV15.  So we are up to the full HEPA MERV 17 in our plans.  And that makes for a system upgrade in most facilities.  In a few cases, a shop with industrial dilution ventilation can be used -- which is even better..

We also, FYI, are finding that employers, if they really want to reopen, can find a way to test employees up to 3 times a week for COVID-19 (not antibodies, etc.)  And we now require level A personnel (those who can't distance or wear a mask due to the nature of their work) be tested three times a week.

Others get tested once a week.  And we are making it stick, Oh ye of little faith.  
Monona


-----Original Message-----
From: Stuart, Ralph <Ralph.Stuart**At_Symbol_Here**KEENE.EDU>
To: DCHAS-L**At_Symbol_Here**Princeton.EDU
Sent: Tue, Jul 7, 2020 8:28 am
Subject: [DCHAS-L] ASHRAE guidance on Reopening Schools and Universities

CHAS readers many be interested in the link to the ASHRAE guidance on reopening schools and universities at
It's a good review of basic concepts and best practices related to institutional ventilation systems, which many people are suddenly interested in.

The challenge I see in using this document is that the design basis for this document is to dilution of (chemical) pollutants to negligible levels. I'm not sure that dilution is a good approach for biohazards such as virus which can survive on surfaces for hours after it is introduced into a space. In the BSL-3 labs I have helped evaluate, direction of air flow was more important than number of air changes per hour.

- Ralph


Ralph Stuart, CIH, CCHO
Environmental Safety Manager
Keene State College
603 358-2859


---
For more information about the DCHAS-L e-mail list, contact the Divisional membership chair at membership**At_Symbol_Here**dchas.org
Follow us on Twitter **At_Symbol_Here**acsdchas
--- For more information about the DCHAS-L e-mail list, contact the Divisional membership chair at membership**At_Symbol_Here**dchas.org Follow us on Twitter **At_Symbol_Here**acsdchas

Previous post   |  Top of Page   |   Next post


The content of this page reflects the personal opinion(s) of the author(s) only, not the American Chemical Society, ILPI, Safety Emporium, or any other party. Use of any information on this page is at the reader's own risk. Unauthorized reproduction of these materials is prohibited. Send questions/comments about the archive to secretary@dchas.org.
The maintenance and hosting of the DCHAS-L archive is provided through the generous support of Safety Emporium.