April 8, 2010

Revising Temperature and Humidity Standards

Max Anderson argues convincingly for relaxed standards for temperature and humidity control for museum collections, noting that current research does not show any adverse affects with fluctuations of humidity from 35% to 65% and temperature from 52 to 88 degrees fahrenheit.  Relaxing the current strict standards would both make loans and exchanges easier, but also significantly reduce costs for HVAC and reduce carbon emissions.

The "gold standard" of strict 70 degrees fahrenheit and 50% (or 55%) relative humidity is only possible with expensive humidification and dehumidification systems (which suck up a lot of power) and require very careful detailing of the building envelope in order to the building itself. Perhaps the costs associated with a changing climate will accelerate the discussion.

This is not a new idea. We have talked about the value of strict temperature and humidity control and the challenges of vapor barriers here before, but it is good to see the discussion getting more attention.

Update:  Here are several other interesting discussions:

The Nothern States Conservation Center on Relative Humidity and Temperature

A piece posted by the National Archives by the father of this discussion, Ernest Conrad: The Realistic Preservation Environment

And here is a good, if technical, discussion of the challenge of Humidity Control in the Humid South.