Cold storage

We are in the process of building a custom-made cold storage vault
(80 cubic metres) for our Collection which comprises largely of
paper manuscripts dating from the early 1900;s and a small amount of
photographic material. The difficulties we face are in determining
the specification and most appropriate combination of building
materials for the vault. We are in a tropical climate (South India)
by the coast where the external temperature ranges from 20-40 deg. C
(70-104 deg. F) and relative humidity ranges between 50-95%
averaging at 70%.

Our proposed specifications for the vault are 10 deg. C +/- 2 deg. C
and relative humidity at 45% +/- 5%.  We are told that it is
difficult to maintain a stable RH below 10 deg. C.

Building materials that have been suggested are:

    1.  For the outer vapour barrier: aluminium foil on tar

    2.  For temperature control: Polyurethane foam (3-4inch)/glass
        wool

    3.  For the inner walls and ceiling: aluminium sheet/stainless
        steel sheets/powder-coated galvanised iron/gypsum
        blocks/gypsum sheets/plaster.

We seek an optimum solution which leaves as much space as possible
for our Collection and would be grateful for any advice and
comments.

Barbie Dailey
Sri Aurobindo Ashram
Archives & Research Library
Conservation Lab
Pondicherry 605002
India


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                  Conservation DistList Instance 13:48
                  Distributed: Friday, March 24, 2000
                       Message Id: cdl-13-48-032
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