Insulated modular storage without environmental controls

Paula Sagerman <redfish [at] together__net> writes

>The Brattleboro Historical Society (VT, USA) would like to use part
>of an old barn for storage of archival materials if there is a way
>to protect the materials from deterioration.  We have paper,
>textiles, furniture, etc.  In order to protect the building
>envelope, we are considering building a "box within a box" using
>insulated, sheet-rocked walls and ceiling.  However, there will not
>be any climate control. Are any materials safe in this situation?

I do not think that this is a good idea. Although the collections
would be protected from dust, insects, and rodents if the enclosure
is well constructed, I worry about temperature and humidity build-up
in the summer. Although an insulated structure will warm up more
slowly in the summer, it will also hold the heat for longer. In
turn, once humidity penetrates the enclosure, it will be held inside
for a longer period of time, possibly causing mold growth.

There could also be a problem if the room is entered in the early
spring. In Vermont, the interior will be very cold due to low winter
temperatures, and warm humid air entering the space could
immediately condense on artifact surfaces. This has happened in
"green" storage buildings constructed by other museums with the idea
of using no climate control equipment.

Instead, I would suggest designing a practical climate control
system for the sealed room that incorporates a window air
conditioner and an electric heater controlled by both a humidistat
and a thermostat.  There are even window mounted heat pumps that
will do both. Such systems can be run fairly cheaply. I believe the
equipment investment will be well worth the cost in the long run. I
would appreciate hearing other ideas on this subject.

Richard L. Kerschner
Director of Preservation and Conservation
Shelburne Museum
PO Box 10, Route 7
Shelburne, VT  05482
802-985-3348 Ext 3361



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                  Conservation DistList Instance 13:44
               Distributed: Wednesday, February 16, 2000
                       Message Id: cdl-13-44-008
                                  ***