Improving the (museum) indoor climate in a flooded castle

Amerongen Castle, built in de period of 1674-1680, is an acknowledged special national museum with a historic cultural value (Kanjerproject). Next to the monumental value of the building, it has a special collection that exists of for example a ‘Van Meekeren’ cupboard, a valuable atlas called ‘Amsterdam 1724’ and painted portraits of monarchs like Willem de Zwijger. The building and the collection are subject to deterioration. As a result of a flood of the river Nederrijn, the basement was completely flooded with water in 1993 and in 1996. This made the deterioration worse. For a period of approximately a year and a half ICN (The Netherlands Institute for Cultural Heritage) has been measuring the indoor climate in the castle. It appeared that the indoor climate was indeed not favourable for the conservation of the collection. The purpose of the work is to understand the effects of flooding of a monumental building, to understand the impact of visitors and the presence of hygroscopic materials on the indoor climate. Finally the indoor climate of the building should be improved. On the basis of the measurements made by ICN the indoor climate of the different museum rooms was mapped. For the judgement of the indoor climate several techniques have been used, namely the climate evaluation chart, the climate evaluations map and the climate evaluation tables. A simulation model has been used to study the effects of flooding, visitor impact and hygroscopic materials in several museum rooms of Amerongen Castle. Finally the model was used to predict the effects of additional heating. The indoor climate of the building has long been influenced by flooding in the past. Visitors of the mu-seum rooms nowadays influence the indoor climate with their heat and moisture production. Generally, the heat production of persons is normative for the relative humidity in the room compared to the moisture pro-duction. The result is a decrease of the relative humidity in the room and an increase of RH near the cold walls. It appears that the indoor climate also depends for a large part on the furniture of the room. It is sta-bilized by the presence of hygroscopic materials in the room (furniture, carpet, curtains, etc.). The library e.g. has a filled bookcase. The presence of these hygroscopic objects (books) in the library seems to be re-sponsible for the comparatively stable relative humidity, in combination with the use of a mobile dehumidi-fier. Two studied heating systems (humidistatically controlled heating and floor heating) will lead to a more favorable indoor climate. Floor heating will be applied in the basement and the hall and long corridor on the first floor (beletage) and the humidistatically controlled heating system in the remaining museum rooms. The results seem to be promising