Design Engineering Review of Two Canadian Displacement VentilationApproaches with in-situ Performance Measurement of the Buildings

Displacement Ventilation approach is becomingan interesting alternative to mixing ventilationainong Canadian consulting engineers. Thispaper presents two recent DisplacementVentilation projects designed by two inajorCanadian engineering firms. The designapproach chosen by the mechanical engineers isreviewed and compared to European andAmerican existing Displacement Ventilationdesign guidelines. The paper shows that sometraditional mixing ventilation assumptions arestill prevailing which alter the expected benefitsof the Displacement Ventilation approach. Insitu performance measurements from twobuildings during the winter of 2008 arepresented. Thermal comfort and air qualityindicators are assessed and compared to theexpected performance of the designedDisplacement Ventilation system. Majordiscrepancies are highlighted and preliminaryexplanations are given in the light of the mostrecent considerations about this ventilationstrategy.