Requirement and testing of face velocity of fume hoods in laboratories

Based on the requirements for face velocity of fume hoods by some countries, experimentally studies the distribution of face velocity under the two door opening conditions of 500 mm and maximum in height, and at different setting face velocities. Evaluates the performance of fume hood with flow visualization experiments. Concludes that from the point of view of the distribution uniformity of face velocity and control capability to contaminated airflow, the resistance of left and right airflow channels of fume hood should be balanced as well as possible; the face velocity should be 0.4 to 0.6 m/s when the opening height is 500 mm, and less than 0.4 m/s for the maximum opening.