>We are in the early stages of a proposed renovation project. Campus
>planning people are questioning HVAC specifications (plus or minus
>variances on temperature and relative humidity). What are recommended
>variances for art museums today? Are there any published reports and/or
>articles on the subject? I don't want to end up with a facility that due
>to cost restrictions we
>would be unable to accept certain traveling exhibitions and loans due to
>environmental requirements that we were unable to meet.
There are no published "generally accepted standards" that I know of, but
there has been a general consensus that a variation of no more than plus or
minus 2 degrees F is desirable. The desirable level of relative humidity is
specific to the type of object (photographs and paintings prefer different
humidity levels, as do metal objects and leather objects, etc.). A
compromise in the range of 50 per cent is usually suggested. These figures,
or very similar ones, are given in numerous different sources (e.g. G.
Thomson, The Museum Environment, Butterworths, London, 1978), so I always
assumed that they were based on some kind of solid data. Surprise! In 1994
the Smithsonian's Conservation Analytical Laboratory Museum Support Center
published its first (Interim) report on "Mechanics Research on National Air
and Space Museum Materials and Environmental Effects on their Properties".
This is the most significant systematic research to date on the influences
of environmental conditions on museum objects. The conclusions of the
research team are that 1) current climate control standards are not based
on science and 2) a much wider range of temperature and relative humidity
is permissible than is generally regarded as acceptable.
Sample quotes from one of the CAL papers, "Relative Humidity Re-Examined"
by David Erhardt and Marion Mecklenburg:
"The widespread, if unofficial, acceptance of values of relative humidity
in the range 50-60% is because visible damage (cracking, flaking,
distortion, mold) is greatly reduced by controlling the relative humidity
in this range. However, the reduction of damage is at least partially due
to the stabilization of relative humidity and the avoidance of damaging
extremes, rather than to the specific value of relative humidity."
"It is easy to see how RH values around 50% have become so widely accepted.
It is only when less obvious forms of damage are considered, such as the
slow but continuous degradation of organic materials, that lower values of
relative humidity seem more desirable. In fact, the reduction of mechanical
damage is the only major factor that would seem to argue against all but
the lowest values of relative humidity, those below 25-30%. This
conflict--mechanical damage versus chemical degradation, form versus
content--is the main consideration in choosing a suitable RH, and one for
which there is no obvious resolution."
The release of the interim report was reported in a page 2 article in
Smithsonian Research Reports. As someone involved in the design of a new
building at the time, I thought "This is revolutionary. The potential
impact on museum design is enormous." I even called Museum News to ask if
they were considering doing an article on it. (No, it's too new, but maybe
later after there's been some follow-up and some discussion within the
profession). I discussed it with other Museum directors, but it never got
beyond the idea that "Hey, I'm not going to be the first one to build a
museum to new standards--I won't be able to borrow from other museums who
adhere to the old standards. "
Of course, the most important thing for both temperature and humidity is
not a particular level, but consistency. Fluctuations are inherently
damaging. Our new building's HVAC system will seek to maintain 70F and
50%RH.
John Vanco
Erie Art Museum
411 State Street
Erie, PA 16501
Phone 814-459-5477
Fax 814-452-1744
PLEASE NOTE THE NEW E-MAIL ADDRESS
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John Vanco
Erie Art Museum
411 State Street
Erie, PA 16501
Phone 814-459-5477
Fax 814-452-1744
PLEASE NOTE THE NEW E-MAIL ADDRESS
[log in to unmask]
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