Re: VENTILATION AS BARRIER FOR AIRBORNE AREA

[Tony Hedges <loui19@vcomm.net>]

At 04:59 PM 4/12/96 -0500, you wrote:
>     I am revisiting this topic because I believe I was not specific enough 
>     about the geometry of the situation.  Several suggested using the 
>     heavy plastic strips found on grocery refrigerated compartments that 
>     would provide separation while still allowing equipment passage.  
>     Others commented that such a large opening meant the two rooms were a 
>     single airspace so a barrier that provides a complete seal and a DP of 
>     up to 1 inch of water was needed.
>     
>     Jackson_R_Ellis@rl.gov
>
>
Jackson,
  Sorry for the late response, I've been busy with a plant outage.  You have
several options available depending on the ventilation systems in place.  I
recently attended a course on Industrial Ventilation.  I looked through the
textbook: "Industrial Ventilation - A Manual of Recommended Practice, 22nd
edition" by the American Conference of Govermental Industrial Hygienists for
a formula for your situation.  Without more specifics on the systems in
place I'd just be guessing.  As long as you have air flow from the "tunnel"
into the room you are confident that the airborne area is staying in the
large room, correct?  With that in mind, I recommend the following:

  1) Determine the air flow in the large room and the tunnel by using
"smoke" tubes.       These tubes generate a smoke when air is passed through
them.  The smoke travels      with the air currents and allows you to easily
determine the air flow in a room.       I have used tubes manufactured by
MSA.  Remember to test in all areas of the           building for the
different ventilation modes that may exist.  For example: doors       open,
heating building, or cooling building.

  2) Enclose the airborne generating activites.  This may be in the form of
a "tent" or      enclosure that has filter ventilation supplied.

  3) Position a continuous air monitor in the tunnel to provide an early
warning of
     an airborne condition in the tunnel.

Hope this helps.  If you have any questions, please e-mail me.

Tony Hedges
RPT
loui19@vcomm.net