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Re: GBlist: How to outgas a new building?




In a message dated 9/21/97 10:20:01 AM, marmac1@worldnet.att.net wrote:

>Does anyone have references or information on how to outgas a new 10 story
>office building by heating it up to outgas or any other methods?
 Snip............................

I agree with John Salmen that there are dangers associated with heating up
all the materials in a new building for the purposes of accelerating
offgassing.  You are unable to control synergistic chemical reactions,
structural and other damage.  John Girman's studies and others have shown
that the type of "baking out" you are talking about is fraught with
complications and problems. To accelerate offgassing, the building materials
must be heated to a temperature (85 to 103 degrees F.) beyond their designed
capacity and maintained at that temperature for a minimum of 72 hours (longer
is more effective).  Fresh air ventilation must be maintained simultaneous to
the heating in order to exhaust the noxious offgassing.  The balance between
temperature, fresh air intake and stale air exhaust must be continuously
monitored and the entire space must be professionally inspected 24 hours a
day during the bakeout period.  Windows can crack, drywall nails can pop out,
doors can warp, adhesives can break down, laminates can separate, electronic
or other equipment can be damaged, and warranties can be voided.  Worst of
all, the released destabilized chemicals and odors may be absorbed in
fabrics, acoustic ceilings, or other absorbent surfaces--only to continue
offgassing into the rooms for a long time into the future.

Far better approach for indoor air quality is:
1- Source reduction.  Eliminate as many toxic surfaces and furnishings as
possible.
2 - Isolate compromise materials from the indoor space (air barriers,
sealers, separate locations).
3 - Provide spot exhaust ventilation for problem equipment, such as
computers, copiers, etc. and provide well-designed, controlled ventilation
for the building.  Utilize high quality filtration to neutralize foul air.
 As John Salmen said, the ventilation design is a most critical element.
4 - Flush the space with total fresh air, exhausting stale air, for as long
as possible before occupancy.
5 - Run the HVAC system (with fresh air component and high quality
filtration) for a period of time each day before occupying space.  Maintain
positive pressure in rooms.  Monitor conditions and occupant health.
6 - If possible, provide operable windows for individual occupants.

By the way, this is not an analysis or a prescription--it is just what comes
to mind as a quick response to the query above.  I think it is important to
think very carefully before jumping to conclusions about the best "fix" for
such a building.  There is plenty of literature for further information.

David Kibbey, Environmental Building Consultant
1618 Parker Street
Berkeley, CA 94703
phone/fax:  510-841-1039
email:  IAQKibbey@aol.com



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