A novel method to measure the air entrainment ratio of an active chilled beam

The paper presents a new simplified method to measure the air entrainment ratio of an active chilled beam or induction unit. The method uses a single anemometer and a simple purpose built measurement venturi together with the primary air flow rate. The new method is described and its calibration procedure is explained. Measured results are compared with results obtained according to pr EN15116 with 2 extra sensors measuring the after coil air temperature. Results show that the new rectangular venturi method produces reliable and consistent results.