Abstract
State of the art hood design supposes that the required rates of exhaust can be calculated using a simple centerline formula. A design based on this simplification carries the possibilities of poor capture efficiency or aerodynamic efficiency. In this paper, the theoretical and experimental determination of three dimensional velocity contours for right quadrilateral exhaust hoods is reported. The results show that the theoretical equation can be used effectively to quantitate the three dimensional velocity contours, thus opening possibilities for optimization of hood design with respect to both capture and aerodynamic efficiencies.