Comparative assessment of external and internal insulation for intermittent air-conditioned bedrooms in Shanghai

A comparative assessment of external and internal insulation for an intermittent air-conditioned bedroom was performed numerically. A bedroom in Shanghai was used for the numerical calculations and two operation modes were assumed. The energy for the on-periods and the thermal comfort index during the off-periods were used to evaluate the exterior walls insulation configurations. The study shows that, the energy used for heating was significantly reduced by adding insulation layers on the surfaces of the exterior walls. The energy used for cooling was also decreased with the increasing insulation layers even though the exterior walls insulation seems have little impact on the amount of energy decreased. The external insulation configuration gave better thermal performance compared to internal insulation configuration, when measured by both the annual cooling and heating energy requirements. Using the thermal comfort index as criterion, for a given total thickness of insulation layer, the better performance was obtained when placing the insulation layers at the outdoor surface. (c) 2017 The Authors. Published by Elsevier Ltd.