In the paper, the COMIS-LDSM program was developed that the COMIS code was revised to calculate the discharge coefficients and airflow rates at inflow and outflow openings for arbitrary wind direction. Wind tunnel experiments were performed to validate the prediction accuracy of ventilation flow rates using the COMIS-LDSM and the conventional method. The conventional method overestimated the ventilation flow rates compared to those by COMIS-LDSM, especially when the approaching flow was not normal to the upwind openings. The simulation study was also carried out to calculate ventilation flow rates at a typical detached house in Tokyo in the intermediate season. The cumulative air change rates in the detached house calculated by COMIS-LDSM were predicted by reduction of 4% compared with the conventional method.
