Abstract
To make an evaluation of ventilation systems, numerical computation was carried out for three dimensional, isothermal, and turbulent flow schemes. It was found that there exists an optimum position for an inlet in relation to an outlet whereby the most effective ventilation can be attained. In addition, similar to the results for the two dimensional computation, the slope of the concentration decay is virtually constant and independent of the position in the room, so the mixing factor derived from this slope can be used as an index of the ventilation efficiency. Further, three dimensional computation seems to be necessary for a quantitative estimation of the mixing factor.
