Soot and odour removal after a fire

Just a couple more observations:

    1. I agree with Nigel Seeley--I think ozone is best kept away
        from collections.

    2. Unfortunately, the vapour pressure of the odiferous
        substances is independent of the total pressure, so reducing
        the air pressure won't increase the rate of evaporation. The
        best thing to do is ensure that air can circulate freely
        over the objects and the absorbent material, preferably
        using a fan to make sure there are no dead spaces.

    3. All sorbents, such as zeolites and molecular sieves, give out
        heat when they bind water molecules.  Normally the rate of
        absorption of water vapour, and thus the rate of production
        of heat, is slow, so a rise of temperature is not noticed.
        But even dry silica gel gets hot if you drop liquid water on
        it.  As I said before, I would favour activated charcoal for
        the purpose of odour removal, as it doesn't bind water
        vapour strongly.

Barry Knight
English Heritage
London


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                  Conservation DistList Instance 16:20
                Distributed: Monday, September 16, 2002
                       Message Id: cdl-16-20-003
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