European Standard - EN14175 : 2003
The European standard is different from ASHRAE in many ways. As a special requirement the EN test measures fume hood performance when there is a disturbance in the airflow patterns in front of the hood (which is the case when someone walks by etc.)
Inner Grid Test
This test uses a special setup of sampling tubes arranged in a grid to measure the concentration of a tracer gas at 6 different positions inside the hood.
Outer Grid Test
This test uses an apparatus similar to the inner grid test to measure concentration of the tracer gas at a number of critical positions outside the sash.
Robustness Test
This is the key test in the EN regime. A plate measuring 0.4 x 1.9 m is crossed in front of the fume hood at 1 m/s for 6 times, with the sash in the open position. The sensitivity of the hood to this disturbance is
determined.