Conservation looms large in discussions about museums’ sustainability, not least because air conditioning is often heavily used to maintain internal climate conditions.
Christian Baars, the head of collections care at National Museums Liverpool (NML), says that despite being closed for months during Covid lockdowns, his organisation’s museums saved hardly any energy. He believes this was to a large degree because of the link between conservation and air conditioning.
But Baars says there is still huge potential for energy savings in NML’s buildings.
In his former role as senior preventive conservator at National Museum Cardiff, Baars contributed towards a significant reduction in energy use. The museum, which is part of Amgueddfa Cymru (National Museum Wales – NMW), reduced its energy use by almost 70% over about 15 years by using
a forward maintenance plan. When equipment was coming to the end of its life, the estates and conservation teams assessed how best to replace it based on energy efficiency, maintenance costs and environmental control needs.
This included replacing more than 50 steam humidifiers with more efficient ultrasonic models in 2019, which is expected to save £90,000 a year in bills and maintenance costs.
Baars says that it helped to think holistically. There were discussions about buying a bigger cooling plant to bring the temperature down in one gallery. But eventually a solution was found by replacing the old lighting with LED lights, which generate far less heat and meant the old cooling plant could be retained.
“By removing the problem, rather than just dealing with the symptoms, the museum saved a lot of money,” he says. “Everybody wins, including the climate and the environment.”
Robert Pearce, principal preventive conservator at NMW, says a persistent focus on sustainability has reduced energy use and costs across the organisation. In many places, NMW has turned off climate control measures completely where systems were previously running 24/7, after monitoring found that “the environment naturally stays within the parameters we’re looking for”.
“At the collections centre at Nantgarw, NMW’s main storage facility, most of the air conditioning has been turned off, saving a huge amount of money,” says Pearce.
NMW has also allowed the winter temperature in some galleries to drop lower than previously, saving energy and keeping humidity naturally higher. This aligns with wider sector efforts to adopt more flexible environmental standards: the Australian Institute for the Conservation of Cultural Material relaxed its temperature and humidity guidelines in 2018.
But as the climate emergency leads to rising global temperatures and more frequent extreme weather, museums will need to keep monitoring how they manage their internal conditions.
In December, the Victoria and Albert Museum (V&A) began data analysis to inform its approach to collections care and sustainability. Bhavesh Shah, a data scientist at the London museum, correlated readings on light, humidity, and temperature with weather data from the Met Office, to project future gallery conditions.
“Based on that, we can talk about how much cooling, heating, dehumidification and humidification we’ll need in the future,” he says.
The analysis helps identify objects that could be at risk by highlighting likely hotspots or areas with dry or humid conditions. A Michelangelo wax sculpture is removed from display from April to September, but Shah says it could be removed for longer if outside temperatures rise.
Even with a good understanding of the problem, finding ways to keep collections safe in a changing global climate is tricky, given the high energy and financial costs of cooling and dehumidification. Many believe that conservators’ natural instinct to preserve offers part of the solution.
Fran Coles, the conservation and documentation manager at Bristol Culture & Creative Industries, says that rather than focusing on mechanical intervention, conversations on climate control are increasingly looking to “broaden what we know to be acceptable, but also how we can do that in a passive way – how we can use the building materials and the way the building works to maintain the environment”.
On the same theme, Shah says although the air vents on the V&A’s Victorian building have long been blocked up, they could be reopened to help manage conditions.
“You could go back to an older way of doing things,” he says.