Analysis and modeling of building thermal response to investigate the e ect of boundary conditions

Thermal load simulation and sensitivity analysis are performed for a building in Tehran by numerical means. A heat conduction equation of the walls, together with appropriate convection and radiation boundary conditions, is simulated numerically to compute temperature distributions in the walls. This research proposes a heat balance method, coupled with a bulk model, to calculate the building thermal load. In the rst step, the results of the building thermal load for weather data of Tehran are compared and validated with those of Carrier HAP software, and a good agreement is found between them. The building thermal load depends on the boundary conditions of the building. The in uence of the boundary conditions, such as the emissivity of interior and exterior surfaces of the walls and convective coecients, on the building thermal load, is investigated through the application of a sensitivity analysis. Then, the sensitivity coecients, which demonstrate the signicance and impact of internal and external boundary conditions of walls on the thermal load of the building, are calculated, numerically, using a nitedi erence method. The results show that internal radiation is an important component of the building energy balance.