Sometimes the work of managing the BRLSI’s collection is filled with discoveries and excitement, and sometimes it means poring over temperature and humidity charts and tweaking the settings of our dehumidifiers and heaters. In some ways the latter activity is more important than the former, after all without careful climate control these wonderful objects may not be here to inspire others in future centuries.
We dispensed with horse hair thermo-hygrographs some years ago, in favour of electronic data loggers which are smaller, easier to calibrate, and remain accurate for longer. We control the climate through dehumidifiers and oil filled radiators and endeavour to maintain conditions within a range of 10% relative humidity and between 16 and 22C. Each store requires a slightly different range dependent upon the material stores. Ideally metals need very low relative humidity (bellow 40%) while book bindings ideally sit between 50 and 60% RH. Of course mixed materials in our stores mean making some compromises, and long warm wet summers can be challenging, but generally we manage to keep the stores quite stable and bellow the dreaded 70% RH, at which point mould can begin to grow.