Investigation of the Thermal Environment Inside the Shelter for a Decorated Tumulus in Japan

ABSTRACT

Among more than 600 decorated tumuli in Japan, we focused on Hinooka tumulus in Fukuoka prefecture. In order to preserve the stone chamber and paintings, a reinforced concrete shelter was built in 1964 on the stone chamber. From the preservation point of view, one of the main problems in the shelter is condensation on the ceiling especially in winter. In order to understand the mechanism of the formation of condensation in the shelter for Hinooka tumulus and to consider countermeasures to prevent it, the thermal environment inside the shelter was investigated by in situ measurements and computer simulations. Since the relative humidity inside the shelter is almost 100% throughout the year, it turned out that dew condensation tends to occur especially in winter when the temperature on the surface of the ceiling becomes low. The results obtained by computer simulation suggests that the amounts of condensation on the surface of the ceiling can be reduced if the thermal insulation of the roof is increased by adding materials which do not attract pests. Synthetic heat insulation material is one of the candidate materials for reducing condensate on the ceiling of the shelter for the Hinooka tumulus.

KEYWORDS:

• Preventive conservation
• decorated tumulus
• shelter
• on-site measurement
• condensation
• computer simulation

Disclosure statement

No potential conflict of interest was reported by the authors.