Canada's Space Centre in St Hubert, Quebec, is a new 27,870 m2 complex which was awarded first place in the ASHRAE Technology Awards (1996) for new commercial buildings. A dual duct ventilation system was installed to provide a comfortable and pleasant research environment. Dual duct systems, which are the heart of the mechanical concept, provide high indoor-air quality, along with design flexibility, energy efficiency and low capital costs.

This study focuses on the way to apply CEN test methods to a full range of air diffusers and is dedicated to the improvement of these methods proposed by the CEN TC l 56/WG4 of which both authors are members. Air terminals of different sizes have been tested on aerodynamic and acoustic aspects both in a Spanish and a French laboratory. The tests were made according to pr EN 12238 ''Air Terminal devices - Aerodynamic testing and rating for mixed flow applications" and to EN 25135 (ISO 5135).