Hygrothermal analysis of a museum storage room for metal cultural artifacts: Quantification of factors influencing high humidity

Abstract

Several methods for appropriate control of the hygrothermal environment in museums to prevent the deterioration of cultural artifacts were presented in previous studies. However, few detailed hygrothermal simulation models have been used considering the hygrothermal performance of building components and airflow through gaps. Furthermore, hygrothermal properties of a type of storage facility with buffer spaces prevailing in Japan have not been quantitatively evaluated. The objectives of this study were to develop a detailed numerical model of a museum storage room with buffer spaces exhibiting high humidity during summer and to quantitatively evaluate the potential factors causing it; the inflow of humid outdoor air and indirect cooling caused by the air-conditioning system of a surrounding room. We analyzed the simulated temperature and humidity for various cases in which each influencing factor was suppressed. The humidity was reduced when the exhaust fan for the surrounding rooms was stopped or the windows were made airtight, but it hardly changed when the cooling ducts and the reinforced concrete beams were insulated. Thus, the high humidity in the room was attributed to the inflow of humid outdoor air accelerated by the ventilation of surrounding rooms. Although indirect cooling had a small impact on high humidity, its impact on energy loss could still be significant.