Dry air preserves valuable books by Carl Von Linné

Strict conditions required to store priceless treasures

In Växjö, where Linné went to school, the public library is exhibiting a number of his most important works. An important collection of his books, and his genuine diary is archived in the basement. Two minor rooms are protected like a safe, and conditioned in accordance with the recommendations from the National Archives of Sweden, namely keeping the temperature at 18°C (± 2°C) and a relative humidity of 30-40% RH (±5% RH) all year round. These conditions protect the irreplaceable books against damages related to high and fluctuating humidity, which has already taken its toll on fragile paper documents and leather bindings that are more than 200 years old. The Munters solution A Munters ML Plus system supplies the conditioned air into the two rooms. As the ML Plus system offers the advantage of combining pre- and post-air treatment modules, only one unit was necessary. In addition to the desiccant rotor for dehumidification, the system contains both post-cooler, post-heater and a humidifier for cold winter days. Installed in the basement, the ML Plus was also designed with an air-chilled condenser where the water extracted from the process air is fed to a drain. An elegant, all-in-one unit that creates the optimal climate for delicate artefacts, which will now be protected for years to come without further deterioration.