Experimental assessment of thermal inertia in insulated and non-insulated old limestone buildings

Publication date: October 2014
Source:Building and Environment, Volume 80
Author(s): E. Stéphan , R. Cantin , A. Caucheteux , S. Tasca-Guernouti , P. Michel
The aim of this paper is to evaluate summer thermal inertia in high porosity limestone old buildings. These buildings have to be retrofitted to save energy. Consequently, this paper focuses on the effects of insulation on this property. Monitoring surveys were carried out in an experimental room and in five single-family houses. In summer, thermal inertia may vary in a same building according to the localization of the room and the insulation. The analysis of monitoring data before and after insulation of the experimental room allows to highlight the improvement of thermal inertia of the room thanks to insulation: the decrement factor is divided by 10 and the time lag increases by 4 h. These results are confirmed by single-family houses measurements. The decrement factors of insulated limestone rooms are lower (0.10) than non-insulated ones (0.17) and the time lag increases by 3 h with insulation. Insulation of Tuffeau stone rooms does not cause overheating conditions in summer. These results indicate the benefit of insulation on this passive design. For these buildings, insulation reduces the temperature amplitude in summer and delays the maximum of temperature during the night.