LAUSR

Abstract Due to an uncontrolled indoor climate or a poorly designed climate system, the environmental conditions in historical buildings are often suboptimal for the preservation of works of art. This is also the case for Jan and Hubert Van Eyck's Ghent altarpiece, which is located in one of the chapels of the Saint Bavo Cathedral in Ghent, Belgium. Years of poor conservation conditions have led to an urgent conservation treatment in 2010 and a conservation and restoration campaign that started in 2012 and will continue through 2019. In order to contribute to a better understanding of the state of preservation of the altarpiece and the display conditions and to assess damage risks related to the current location, this paper presents the results of a two-year monitoring campaign of the climate conditions in the glass cage in the Saint Bavo Cathedral in which the altarpiece is displayed. Based on the results of the first year, measures were taken to improve the indoor climate, including the installation of a local heating and humidification system. These new conditions were monitored during the second year of the measurement campaign and are representative for the display conditions today. The results of the second year showed that exposure to high humidity's was effectively reduced but conditions with large short-term humidity variations still occurred. However, given a correct management of the new heating and humidification systems, risks for mechanical damage may be largely eliminated.