Abstract
An experimental investigation is carried out to analyze the performance of canopy exhaust hoods where a soap-bubble method newly developed is applied. By using this visualization method, it is now possible to introduce the effectiveness of the hood and the values of effectiveness are measured quantitatively. The results show that the existing two typical design-methods of canopy hoods have some deficiencies in obtaining reliable performances. In determining a hood capacity, the present analysis includes the effect of kinematic energy carried with contaminated air. This method expressed by a formula provides an effective approach to the design of a canopy hood with an optimal performance for a given rate of contaminants.
