The effect of thermal mass on the cooling load in dwellings in a moderate climate

To obtain thermal comfort in a moderateclimate, dwellings were traditionally providedwith a heating system, but few had coolingsystems. The heat in summer was kept out ofthe building by an appropriate building design.Since larger windows and less compactbuildings have become more fashionable,overheating in summer is more problematic.Currently, cooling systems are increasinglyinstalled to improve thermal summer comfort.As a reaction to this increase, producers ofbuilding materials with a high thermal capacityhave promoted their products for the ability tocreate a more stable indoor temperature. Theuse of these materials is therefore assumed tocontribute to a more comfortable summersituation.In this paper the results of a parametric studyof dwellings in the context of Belgium arepresented, analysing the effect of thermal masson the cooling load. For the analysis, dynamicenergy simulations are executed in EnergyPlus.The influence of a number of parameters suchas dwelling type, orientation, glazing, insulationlevel and ventilation patterns on the coolingload is analysed. This is done both for dwellingswith and without thermal capacity to investigatethe importance of the latter.In this paper the results of the parametricstudy are shown. Thermal capacity proved toimprove thermal comfort in summer conditionsin a moderate climate like Belgium and incombination with ventilation it can avoid theneed for cooling. Tn winter situation however,some first simulations indicated that thermalcapacity leads to a higher energy demand for anintermittent heating schedule. The mostimportant findings are summarized and someaspects remaining for further investigation arehighlighted.