Influence of exhaust hood area on limit flow ratio for push-pull ventilation under condition of exhaust hood area smaller than supply hood area

 Develops an experimental platform in the push-pull ventilation laboratory, whose exhaust hood area is smaller than supply hood area. Under the condition of the same parameters, determines the minimum exhaust air rate that completely discharges the given supply air rate by the tracer gas method, and deduces the limit flow ratio. The experimental results show that under the above experimental conditions, the change of exhaust hood area will affect the limit flow ratio, and the larger the gap between the areas of the exhaust hood and the air supply hood, the higher the limit flow ratio.