Abstract
In a multistory building, "Draft phenomenon" is caused by temperatures fluctuate in the inside and outside of the building etc.The necessity for verifying prior about various problems that this draft phenomenon causes has risen. A simple simulation model in the entire building is made to understand the outline of the influence with exhaust fan of shape, the air leakage efficiency of the building each part, and each floor installation, the ventilation analysis is executed, and it reports on the result of the evaluation..
