Back from a much-needed, long break to bring you a blog about what has been a very hot (and cold) topic lately: climate control for collections. I have been learning so much about climate control in the last couple of years with the plethora of research that has surfaced (and re-surfaced) on the topic. This post attempts to summarize the important points of the history of climate control for cultural heritage, and discusses why this is important not just for large institutions, but for private conservators as well.

In the last century we arrived firmly at the idea where creating ‘ideal’ environments would prolong the life of artwork. This begs several questions: what is the ideal environment? Who defines ideal? Where and for what is this most applicable? Does it follow then, that art that was made in an arid climate for example, should not be stored in that arid climate because the local environment doesn’t align with the ‘ideal’ preservation range for the used materials?

The discussion of climate control in museums began in the early to mid-20^th century. One of the first notable assessments, and an early set of guidelines was by F.I.G. Rawlins, a British physicist. In his assessment he suggested that 60% relative humidity and 60°F was the ideal standard for prolonging the longevity of artwork. This in itself was based on a loose assessment from the 1930s, suggesting parameters that were based on the authors’ local environment specifically in winter months in England. Rawlins’ publication was inadvertently accepted as the climate control tome for the next 50 years. Following this, Garry Thompson wrote The Museum Environment in 1978, the contents of which were taken literally, but his parameters were intended to be loose guidelines, according to Stefan Michalski. Since then, the energy used to meet these impossible perceived standards for ‘preservation’ and storage (which are often not met in practice) has become the biggest carbon emissions contributor of museums and collections.

Near the end of the 20^th century, the Canadian Institute for Conservation, with the influence of Michalski, created new guidelines, and in 1999 the ASHRAE handbook for HVAC applications was created by and for engineers and conservators to work together and understand the needs of buildings and their collections alike. If you’re interested in reading, it has an entire section for local climate considerations, as well as chapter for cultural heritage institutions specifically (link to handbook below).

In the early 21^st century we saw museums begin to adopt new guidelines better suited to their needs, the Bizot group made suggestions, Stephen Hackney encouraged micro-environments as a reliable alternative, and we also saw work continue to materialize from many others in the field on the topic as concern grew for the effects of climate change on cultural heritage and global environments. ICOM-CC and IIC jointly wrote a statement on climate control in 2014, which was meant to be just that: a statement, but instead it was received as another guideline.

What is ‘best’ for one collection is not necessarily ‘best’ for others, and it is now an increasingly more common view that it is unnecessary for all thermostats and humidity readings to all be set at the same specs around the world. Air conditioning wasn’t invented until the 20^th century, and artworks have been successfully preserved without it in a variety of climates for a very long time. This is not to say that we do not deeply appreciate air conditioning in the depths of summer, but rather to say that it is a tool we have not historically had the convenience or luxury to rely on.

As conservators and cultural heritage professionals are aware, objects will inevitably undergo changes over time, and there will inevitably be some kind of damage; but perhaps measuring and managing it is more reliable than attempting to eliminate it completely. Some museums now have mandatory sustainability training, such as the Horniman in the UK, allowing all staff to understand the parameters and purpose of climate control and climate control adjustments.

Many of the institutions such as the Horniman, Rijksmuseum and several in Denmark, as well as an increasing number of institutions globally, have adopted the Bizot guidelines. Creating the ‘ideal’ interior environment costs a lot more than you think it might- not only financially, but the carbon footprint of climate control in a museum can often make up to half of the entire footprint of the building. Realistically it is exceptionally difficult to maintain the narrow standards that have been set as the acceptable range within museums. It has been proven in fact, that when the temperature range is widened, the relative humidity also stabilized more than it previously had (see Conversations with Changemakers link below). Controlling an environment does not have to necessarily include rigid parameters, and widening the range can save money and reduce the carbon footprint of studios, museums, etc.

The majority of the data and research available on this topic has come from museums and large institutions, but can be applied to private studios and small businesses as well. Private studios often have a relatively high turnover for artwork, receive paintings from a multitude of different environments, and must consider the climates that each artwork has been received from and is being delivered to. This is no easy feat! As a starting point, private studios can consider the above-mentioned seasonal changes to thermostat settings, and work from there.

As Pamela Hatchfield so aptly said at the Climate Control Conference, it’s no longer a question of whether we should broaden parameters, but rather by how much the parameters should widen. Though large institutions have an appropriately much larger impact than small studios, the consideration of the climate emergency in our every day operations as private conservators can make a world of difference.

Thanks for reading!

For the sake of brevity, I did not include commentary on the design of HVAC systems, different kinds of environmental monitoring systems, etc. Maybe in another blog, another day!

Resources and further reading (and watching):

AIC-FAIC Sustainability Committee (2023) Strategies for Reducing the Energy Consumption of Buildings. Conversations with Changemakers. 22 February 2023.

Ashley-Smith, J., Burmester, A., & Eibl, M. (Eds.). (2013). Climate for collections: Standards and uncertainties. Postprints of the Munich Climate Conference, 7 to 9 November 2012. Doerner Institut. https://s3.eu-central-1.amazonaws.com/thenetexperts-pinakothek-cms/06/climate-for-collections.pdf

ASHRAE (2023). Chapter 24: Museums, Galleries, Archives and Libraries. ASHRAE Handbook – HVAC Applications. https://www.ashrae.org/technical-resources/ashrae-handbook

Hackney, S. (2004). Paintings on Canvas: Lining and Alternatives. Tate Papers. Autumn:2. https://www.tate.org.uk/research/tate-papers/02/paintings-on-canvas-lining-and-alternatives

Horniman Museum and Gardens. (n.d.). Climate and Ecology. https://www.horniman.ac.uk/about-the-horniman/climate-and-ecology/

Lukomski, M. (2023) Speaker, International Climate Control Conference. YouTube.

Michalski, S. (2007) The Ideal Climate, Risk Management, the ASHRAE Chapter, Proofed Fluctuations, and Toward a Full Risk Analysis Model. Contribution to the Experts’ Roundtable on Sustainable Climate Management Strategies. https://www.getty.edu/conservation/our_projects/science/climate/paper_michalski.pdf

Rawlins, F. I. G. (1954). Physical methods in the care of museum objects. Physics Bulletin, 5(52), Article 004. https://iopscience.iop.org/article/10.1088/0031-9112/5/52/004

Shah, H. (2019).The Unexpected History of the Air Conditioner. Smithsonian Magazine. https://www.smithsonianmag.com/smithsonian-institution/unexpected-history-air-conditioner-180972108/