Thermal assessment of the behavior of retrofitted rammed earth in central Catalonia

Abstract

Compliance with the Spanish Basic Document on Energy Efficiency (DBHE) in some cases contributes to highlighting the deficient thermal resistivity of rammed earth walls, despite the thermal gains resulting from their great inertia. The conductivity values for walls between 30 and 60 cm thick range from 0.6 to 1.6 W/mK (Bauluz & Bárcena), depending on density, amount of clay, and type of soil. This research carries out an in situ analysis of the indoor ambient parameters of a restored rammed earth rural home in central Catalonia. A dynamic analysis is carried out of the different real thermal values, which are contrasted in different positions in order to take into consideration its good diffusivity, inertia and thermal accumulation capacity over extended sequential periods to apply the theory and practice according to HE1. Seven dataloggers were used to measure the different variables of the facade with the most solar exposure in the summer every half hour. Finally, the thermal transmittance values obtained for the rammed earth wall differed greatly from those suggested in the theory and short-term laboratory tests. © 2018 Taylor & Francis Group, London.