Conference Paper
Proceedings of ASim Conference 2012: 1st Asia conference of IBPSA-China, Japan, Korea
Radiative heat transfer simulation between outdoor and indoor spaces for predicting the performance of a direct heat gain system
Radiative heat transfer simulation between outdoor and indoor spaces for predicting the performance of a direct heat gain system
Hidenori Kawai, Takashi Asawa, Akira HoyanoAbstract: A direct heat gain system, which is an example of a passive system using solar heat, is employed in some buildings in Japan. In order to design a direct heat gain system, it is important to consider the outdoor environment, such as surrounding buildings and trees. In addition, if a building is affected by the outdoor environment, indoor factors such as the position of heat storage materials and windows can be taken into account when designing a direct heat gain system. This study presents a simulation of radiative heat transfer between outdoor and indoor environments for predicting the performance of a direct heat gain system. The solar radiation received by external building surfaces is calculated by ray tracing method, and the solar radiation on the internal surfaces is calculated by taking into account the material and position of the heat storage material and the direction of solar radiation. The calculated solar radiation values are entered into the multiroom heat load simulation to calculate the room air temperature. In this study, the calculation accuracy of room air temperature depends on reproducibility of building geometry in the numerical simulation. This study confirms the effectiveness of the presented simulation model by analysing the influence of these error factors on the calculation accuracy of room air temperature. Finally, this study analyses the influence of outdoor environment and indoor factor on the performance of the direct heat gain system as a case study. The results show that the calculated room air temperature is affected by the solar heat gains, which depend on the outdoor condition, and that the room air temperature fluctuates in response to the position of the heat storage material and window. Pages: 267 - 274 Paper: