Paper Conference

Proceedings of eSim 2018: 10th Conference of IBPSA-Canada


The Effect of Roof Heat Capacity on Heat Gain in Different External Conditions

Milad Mahmoodzadeh, Rouhollah Fatehi

Abstract: In this study, thermal performance of four kinds of roofs with different heat capacity in different external conditions is investigated by numerical simulation using EnergyPlus software. Four roofs which their thermal capacity varies from 167 to 712 kJ/m²K are studied. In addition to the heat transfer rates, the time lags and decrement factors are evaluated to compare the roofs’ performance. The result of this study indicates that increasing the heat capacity of the roof leads to a decrease in the difference between its maximum and minimum loads and decrement factor and also increase in the time lags especially in the dry climate and high-radiation condition. However, the total load reduces slightly only in the high-radiation condition. Also, the external conditions have no significant effect on the decrement factor. Finally, increasing the thermal capacity and solar shading of the roof would be appropriate passive strategies for reducing the energy usage in buildings.
Keywords: Roofing materials; Thermal capacity; Heat gain; Cooling load; Time lags.
Pages: 585 - 593