Region: The Americas

‘A wider pool of HVACR specialists, who understand the needs of museums, would be very advantageous’

Ellen Pearlstein

Could you provide us with an overview on how the optimum climate can ensure the longevity of art pieces or cultural objects in museums, libraries and archives?

There has been an interesting history in the consideration of climate in museums and the impact of climate in museum collection, because there was a very important book published in 1978 by a British author, named Gary Thompson – it’s called The Museum Environment. That book was important in influencing the entire English-speaking world, and it outlined the kind of research done at that point in time. The book was divided into two halves – one was designed for energy engineers, and the other half was for conservation [specialists], who care for collections. It was a very forward-looking book.

The outcome of that book was that some climate specifications were created for temperature and humidity, 21 degrees C and 50% relative humidity, respectively. Those were taken as unyielding standards and accepted by people who cared for collections, because people understood this to be something that was important for their preservation. However, the realization that has been made since the publication of that book is that not every region in the world has the same outdoor environment, so trying to achieve the indoor environment that may be appropriate for a more humid country like England, or a city like London, might not be appropriate for a museum built in a dry part of the world [with] desert climate. The realization that the region in which the actual museum or collection resides is particularly important as a variable, has taken place.

The next thing is that materials that comprise museum objects include a whole range of different materials, and those materials don’t behave in exactly the same way in response to temperature and relative humidity. So, for example, archaeological [objects] that have been buried in salty water have been subject to salts remaining in the materials. When those materials are moved into museums, the salts left behind can be very reactive and responsive to changes in relative humidity. We know archaeological metals and ceramics and some stone materials can have particular sensitivities, and certain kinds of archaeological and historical glass have particular sensitivities, and other materials like ivory and wood are sensitive to changes in relative humidity.

I would say in the last 25 years, more research has been done, and continuing research is going on now, to look at exactly what kind of damage is created when you did not have tightly controlled temperature and relative humidity. One major study was by the Smithsonian Institution in the United States, another by the Canadian Conservation Institute and yet another significant study was by Getty in Los Angeles, called ‘Managing Collection Environment’, and all of the studies are designed to look at whether, or not, you can safely relax the climate standards for museums, so that the relative humidity could be actually 35-60%. There is wide agreement that 1) it depends on the climate where the museum is, because collections acclimate to the environment they are in to a certain extent, and 2) it depends on what are the collection materials, and 3) everyone agrees that the most important thing is to only permit change in relative humidity, if it happens gradually. What is dangerous for a collection is one day your relative humidity is 15% and the next day it’s 60%, because that’s a very dramatic shift.

In view of the research that has been carried out on the effects of relative humidity and temperature, has there been a move to develop minimum standards that global or regional museums, and similar developments, would have to comply with? Or is it mostly an independent move by galleries that impose their own quality standards for their collections?

It’s a good question. So, museums develop their own standards, and they work to comply with those standards. As you might imagine, standards for climate become crucial when one museum lends materials to another museum. If the Louvre maintains a certain climate for materials and sends them to Abu Dhabi, they are going to be very aware of how the museum in Abu Dhabi maintains the climate around those collections, so museums are very active in developing loan documents, and they specify climate within those loan documents.

Also, in 2014, the ‘Declaration on Environmental Guidelines’ on the museum environment was endorsed by two professional organisations. One is called ‘International Institute for Conservation’ and the other is ‘International Council on Museums – Conservation Committee’. The Declaration is available online; it actually redefines the international standards.  

In such cases, management is very aware of the importance of implementing these standards in terms of building design and equipment choice, but, given the unique requirements, are the FM and operations personnel aware and properly trained on these issues, as well?

It is a case-by-case basis. I would say larger museums with larger operating budgets – they do have a facilities manager, who has a certain kind of sensitivity to the task of preserving the collection. They understand that the climate and HVAC systems installed need to be those that can be adjusted to maintain a safe climate for the collection.

I have visited smaller museums that don’t have the expertise or the resources to necessarily support the kinds of climate requirements that museums demand. Also, there are individuals who create their own specialization – they tend to be HVAC engineers and HVAC specialists with a particular interest in museums and libraries and archives, places that hold important collections. They then can be hired by smaller institutions that don’t have their own expertise in-house. Or they can hire those experts to work with FM that they do have on staff, who may want more information about the specialized needs.

I think, in particular, having a wider pool of educated HVAC specialists, who understand the needs of museums and collection, would be very advantageous. It would help smaller museums that cannot have these people on staff. 

Do you believe that a collaborative approach would move the dial in terms of cultivating more specialists who are aware of the unique requirements of such a development?

Yes, I see more room for collaboration. I think it would be beneficial if facilities engineers were open to working with conservators and curators and collections managers, because there’s a lot we can learn from each other. I always try to invite a facilities engineer into my class and have them talk about how they make decisions, so my students can be in dialog with them. I put collections people and facilities people in dialog.