Experimental study of the influence of thermal mass on thermal comfort and cooling energy demand in residential buildings

The article presents the results of experimental research carried out in two real-scale detached energy-efficient single-family buildings designed to be almost identical with exempt to the construction of their external and internal walls; lightweight skeletal versus traditional masonry construction. The reduction of the average indoor temperature during the heatwave of August 2015 obtained by increasing the thermal mass of the building was 2.8 +/- 0.34 degrees C, with the maximum value at the hottest part of the day being 3.4 degrees C. Replacing the lightweight frame structure of the walls with cellular concrete, in an exceptionally warm August, with an average outside temperature of 22.5 degrees C, shortened the total time of occurrence of indoor temperature higher than 28 degrees C from 18.6 days to only 8 h. The cooling effect of building thermal mass remained stable during all 14 days of heat wave with only slight diurnal variations. The total reduction in the cooling energy demand achieved was 67% at 25 degrees C set point temperature and 75% at set point temperature 26 degrees C respectively. (C) 2020 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license