Museum Showcase Characteristics

The creation and maintenance of an effective microclimate is dependent on the characteristics of its enclosure or showcase. Every microclimate application must take into account a unique combination of aesthetics, conservation, and display and storage policies.  Great care must be taken to plan for, predict, and measure the effects of leakage, lighting, construction materials, and humidity control systems. The importance of enclosures on microclimate control cannot be overstated.

Enclosure characteristics (especially air exchange rates), along with ambient humidity and temperature are the primary indicators when considering microclimate control.  Air leakage rates that might seem inconsequential in an everyday environments can have profound effects on a “sealed” museum showcase. Air leakage rates are driven by a variety of factors, and will vary on the same enclosure with changes in ambient conditions.

We can assist you in understanding the microclimate effects of enclosures, as well as provide the guidance, products and skills needed to create and maintain the optimum and most cost-effective microclimate environmental control for your application.

Below you will find a number of links to informative articles on the interdependence of museum showcases and microclimates:

• The RH calculator will predict the RH in a showcase that is fed with a positive pressure microclimate generator, such as the Mini One or Maxi series units.
• For a look at the history of microclimates and museum showcases, click here for a paper on Trends in Microclimate Control of Museum Showcases by Jerry Shiner, presented at the Conference on Museum Microclimates in Copenhagen in 2007.
• Museum Display Cases and the Exchange of Water Vapour by Peter Brimblecombe and Brian Ramer is a seminal paper on creating a safe microclimate in museum showcases.
• One of the most referenced articles in microclimate control is the classic 1977 Stabilization of RH in Exhibition Cases: Hygrometric Half-time by Gary Thomson.
• With the exception of a handful of oxygen-free display cases (which are usually crafted at great expense and funded by government agencies or grants), all showcases will leak. The Effect of Air Tightness on RH Buffering and Control in Museum Cases, by David Thickett, Philip Fletcher, Andrew Calver and Sarah Lambarth will help you to understand the paramount importance of showcase air exchange rates.
• You may click here for the seminal paper on Case Leakage Testing by Andy Calver, Andy Holbrook, David Thickett, and Steven Weintraub.
• The past few years have seen some radical rethinking of the environments needed for safe storage. Stefan Michalski’s article on the new ASHRAE standards for museums succinctly outlines the basis for these new standards.
• You may also which to read Michalski’s often referenced 1994 article describing in detail the mechanics of case leakage, available from JSTOR
• The articles by Marion Mecklinburg and his compatriots at the Smithsonian Institute are very interesting, as they continue to question the currently applied standards of humidity and temperature control. An excellent start is via the opening and closing remarks to the Conference on Museum Microclimates by David Erhardt, Charles S. Tumosa, and Marion F. Mecklenburg.
• Development of humidity recommendations in museums and moisture control in buildings by JP Brown & William B Rose is fascinating read on the evolution of currently accepted humidity and temperature recommendations.
• Click here to go to our page on Microclimate Control for Paintings and other two dimensional objects.