New approaches to humidity control emerging

The NY Times today has an interesting piece on some new thinking about the role of humidity control in conservation. While they don't go so far as to say 70/50 is dead, there appear to be some new approaches, the simplest being to use more humidity controlled cases and the most interesting being a move towards "smart ventilation," which is essentially going back to how it used to be done before we had elaborate, and now increasingly expensive, HVAC systems. Rediscovering these inexpensive and effective strategies, oddly enough, appears to be the real challenge.

Of course, museums with limited budgets have been finding ways to keep humidity stable for years (fluctuations cause the most damage to sensitive artifacts), the simplest being to seal the space to prevent atmospheric changes from immediately affecting the storage area.


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.

"The Perils of Museum Design"

The Boston Globe has a good piece entitled "The Perils of Museum Design" on the vapor barrier problems at Harvard's Otto Hall, home to the Busch Reisinger Museum. Otto Hall is slated to be torn down to make way for a new Renzo Piano addition to the adjacent Fogg Museum.

Otto Hall was built in 1991 with state-of-the-art temperature and humidity control systems. Unfortunately, this was before architects and engineers fully understood how to keep escaping humidity from damaging the building envelope. Apparently the damage to the building was bad enough that it might have been torn down even without the Fogg expansion. Unfortunately, this kind of problem still happens with newly built museums, but seldom makes the national news. 

A relatively good discussion of wall systems can be found in this educational piece for an air barrier company.

Update:  Sadly, these links are out of date. 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.