Most of us of a certain age will remember where we were in 1982 when Henry VIII’s Warship, the Mary Rose, was hauled out of the sea, from a depth of 36ft, almost two miles south of the entrance to Portsmouth Harbour. It had lain on the sea bed there for 437 years after its sinking in 1545. Once it had been raised, the real work began in its restoration. It wasn’t until 2016 that it was finally revealed in its new home to the public.
“Drying waterlogged wood that has been submerged for several centuries without appropriate conservation causes considerable shrinkage (20–50%) and leads to severe warping and cracking as water evaporates from the cellular structure of the wood”
Managing humidity in art galleries and museums
In the same way, it’s every bit as essential to maintain a consistent level of temperature and humidity in a museum or art gallery. Most older works of art are made from organic materials and as per the Mary Rose, organic materials in almost any form, whether wood, paper, ivory, bone, leather or cotton will potentially be damaged if they become too dry.
The risks to the works drying out are in shrinkage and this can in turn cause joints to loosen. With pictures, this can mean frames becoming loose, misshapen or even paint beginning to flake off.
Conversely, if works become too damp the risks to the works are every bit as high.
With galleries, many of the buildings are old and have high ceilings. They may well be susceptible to damp. These are challenging spaces to maintain across all four seasons with the temperature and humidity variations they bring.
When the temperature rises in a space, the humidity will normally drop, unless additional water is introduced. The air gets warmer and dryer, Again in Winter when it cools down the air gets colder and often damper. This variation is potentially dangerous to artworks.
So, when we work within art galleries and museum spaces, our role is to deliver a consistent level of humidity throughout the entire space to best preserve the works themselves.
Since 2013, the Kimpton Planned and Preventative Maintenance Team have been working with the Lady Lever Art Gallery in Port Sunlight, Wirral to do just this. Manage the temperature and humidity across all of their gallery spaces. For many years prior to this, we had been working with Liverpool Museums – who now look after the Lady Lever Gallery as part of their portfolio.
And they are big spaces.
Funded by the philanthropist Lord Leverhulme (William Lever) and named after his wife, it was opened in 1922 by Queen Victoria’s youngest daughter Princess Beatrice.
In 2018, the gallery welcomed over 200,000 visitors. It’s home to over 12,000 objects and includes some of the world’s finest Wedgwood jasperware and a host of paintings.
The galleries are fitted with a series of mobile humidifiers. These units are mobile evaporative humidifiers as the listed status of the building means there is no option to install a fixed, steam-based or ultrasonic humidifier.
Each unit contains a humidistat (or hygrostat) to maintain the required humidity in the spaces. There are units of different sizes to suit the individual spaces and work together to deliver an overall humidity level throughout. The biggest of these can cover up to 900 M3 on their own. To put that into simple terms, it’s a space that could be as big as 10m x 18m with a 5m high ceiling. To manage this big a space with one unit, shows their competence for the task. In the Lever Gallery, there are over 20 of these units, all that need ongoing maintenance and management, by our team.
Relative humidity in art gallery at Lady Lever Gallery
Museum humidity control at Lady Lever Gallery
Managing humidity in museums and art galleries at Lady Lever Gallery
Monitoring temperature and humidity in museums at Lady Lever Gallery
Museum climate control standards at Lady Lever Gallery
Serious Expertise in Managing Humidity in Museums and Art Galleries