When the origin chapter was rewritten a few editions ago, the rewrite included a discussion of the area of origin as a expanding and contracting area or volume. If you think about it, you can determine the area of origin of any fire incident. That is, the area of origin can be reduced from the Universe to the planet earth to the country to the state to the town to the physical address to the building of origin. The question becomes, is it small enough of an area to be of value in reliably determining the fire cause. That is, is the area of origin determined to be small enough to contain a fire cause that is uniquely consistent with the available evidence?

I would agree that the data you have provided provides evidence of an explosion with a subsequent fire. In your case, it seems to be a reliable conclusion that the area of origin is within the building that was damaged by the fire. With additional data, one might be able to determine a room of origin or a small area of origin. The floor plan and the documented location of the glass windows could provide a reliable means to determine a room of origin where a pressure-rise was experienced. It is also possible that the data may not provide any reliable means of reducing the area of origin.

Douglas J. Carpenter, MScFPE, CFEI, PE, FSFPE
Vice President & Principal Engineer
Combustion Science & Engineering, Inc.
8940 Old Annapolis Road, Suite L
Columbia, MD 21045
(410) 884-3266
(410) 884-3267 (fax)
www.csefire.com