Model-based moisture sorption stabilization in historical buildings

A novel air humidity control technique is proposed for preventing the moisture sensitive materials from varying their equilibrium moisture content, providing in this way more desirable environment conditions for preventive conservation of cultural heritage. The moisture content in artistic works or historical exhibits deposited in historical buildings is stabilized by means of a specific adjustment of the interior air humidity while the annual temperature variations in the interior are left almost unaffected. The proposed humidity control compensating for the impact of temperature changes on EMC variations is based on the application of sorption phenomena models while both the used models are not applied to estimate EMC but to suggest a prevention of its varying. Namely the Kelvin theory of micro-pore condensation and the Henderson model of moisture sorption are applied to determine the so-called equal-sorption humidity control. For long two implementations of this control – in a castle and archives collections – prove the ability of this control to stabilize the moisture content in the preserved exhibits at constant admissible level.