Thermal energy evaluation of building with ceiling insulation in warm-humid tropical climate

Building performance evaluations in real local climate are essential to ensure the effectiveness of methods or strategies implemented to achieve the desirable effects or outcomes. A field study using a test building facility was performed to investigate the benefits of conductive ceiling insulation in real climatic conditions of Malaysia. The objectives of the research were to evaluate building thermal energy performance in four indoor environmental conditions: 24-hour natural ventilation (NV), office-hour (daytime) cooling, residential-hour (night-time) cooling, and lastly 24-hour cooling. The benefits were appraised by analyzing the thermal impact and cooling load (CL) savings. Results show that the degree of benefit and penalty are influenced by the indoor environmental conditions. Ceiling insulation reduced daytime thermal impact but led to night-time thermal penalty due to thermal-lag. The effect was more significant in the attic than the living space underneath whereby in NV mode the attic and indoor temperature was reduced by 4.1 °C and 1.7 °C respectively. In the three cooling modes, the temporal and spatial benefits are evident by the cooling load (CL) savings of 3.65% to 16.88%. Therefore, whist it demonstrated adverse night-time impact, the daytime thermal and energy benefits outweigh the penalties.