The conservation of artworks and hot air heating systems in churches: are they compatible? the case of rocca pietore, italian alps

Most artworks require a stable microclimate and a field study has been undertaken to understand the environmental risks in a mountain church that is heated once a week. The church was selected on the basis of the artworks present and the existing heating system: a hot-air system which is popular due to its low cost and rapid response. The heating system is switched on only during the liturgical services and generates rapid temperature and humidity changes which, in the long run, are very damaging. The temperature stratification leaves people with their feet in cold air, whereas the air in the upper levels is too hot and dry. Moisture condenses on the cold walls. Deliquescent salts in masonry and frescoes undergo dangerous crystallization cycles. Wooden artifacts contract and expand in line with humidity cycles. Deposition of candle and incense smoke is increased, darkening the artworks. The paper discusses these problems, some common errors, and possible methods to mitigate the risk factors.