CFD simulation of airflows and thermal environment in passive architectures - application to a room with Trombe wall system.

Applicability of CFD simulation to designing passive architectures was investigated using a passive solar room with a Trombe wall system inside it. In the investigation non-steady numerical simulation was performed to predict thermal environment in the test room. Two weather models assuming a typical fine winter day were compared, one was the model based upon the data in Osaka and the other was that in Sapporo. The test room has glazing in the south side wall and in the north side one. Each glazing was covered with an insulating door during night. The simulations were executed under the condition that each insulating door was closed with the sunset and was opened at sunrise. This condition realized a highly insulated and air tight space following facts were confirmed through the simulations. Because of the warm climate in Osaka the room averaged temperature θavg is maintained more than 1 °C throughout the day in Osaka while the maximum θavg is less than 18 °C in Sapporo. To maintain the moderate thermal environment in Sapporo, it is sufficient to supply 8 kWh heal input inside the Tromb wall during the night. These results proved the CFO simulation to be one of the useful tools to design various passive architectures