Museum, Art & Antique Humidification - JS Humidifiers - #2

Why humidify in museums & heritage sites?

Poor humidity control can cause irreversible damage to art and antiques made from a wide variety of materials. To provide optimum environmental conditions for preservation, the level of humidity must be maintained between 45-55%rH as well as daily fluctuations controlled to ±3%rH.

It is often a condition of benefactors in deciding whether or not to loan works of art to galleries that these conditions are maintained.

Rapid fluctuation in humidity has the most damaging effect as the materials do not have enough time to acclimatise. These types of changes are difficult to

control in an environment that can be empty one minute and full of tourists in from the rain the next.

The effects may be very visible such as materials warping, splitting or cracking but they can be microscopic. Over time they will become more obvious. As works of art grow older they also become brittle and fragile, and less able to readjust their internal moisture level without damage.

The type of low humidity damage depends on the exhibit but can include the following:

Paintings

Made up from several layers, each individual layer reacts to moisture loss in different ways causing them to blister and the paint layer to flake off.

Paper and papyrus

Although moisture can be put back into these materials once they have dried out, a constant hydrating and dehydrating cycle is not good for the paper structure and can cause damage.

Woods

The amount of damage that will be sustained will be dependent on how the wood was primarily seasoned. However, damage can include warping, cracking and movement of joints, and discolouration of veneers or external veneered layers detaching and becoming loose.

Internal moisture changes can lead to thin elements of the structure cracking.

Textiles

A drop in humidity will cause textiles to become brittle. When stretched across wooden boards or frames there is the risk of tearing. Silk is particularly at risk as are exhibits that contain hair.

Pottery, terracotta & stone

Alterations in the internal moisture content will cause minerals to rise to the surface when wet and then crystallize when dry. This can lead to stains on the surface, powdering and flaking

Why JS Humidifiers?

JS Humidifiers offers a comprehensive service of humidification system design, installation and maintenance. Our range includes spray, steam and evaporative humidifiers and, with over 25 years experience of humidifying healthcare environments around the world, we are ideally placed to advise you on which type is most suitable for your specific application.

Artex Avenue, Rustington, LITTLEHAMPTON, West Sussex, BN16 3LN, UK.

Tel: +44 (0)1903 850200 • Fax: +44 (0)1903 850345 Email: sales@jshumidifiers.com

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