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

摘要

Displacement Ventilation approach is becoming an interesting alternative to mixing ventilation among Canadian consulting engineers. This paper presents two recent Displacement Ventilation projects designed by two major Canadian engineering firms. The design approach chosen by the mechanical engineers is reviewed and compared to European and American existing Displacement Ventilation design guidelines. The paper shows that some traditional mixing ventilation assumptions are still prevailing which alter the expected benefits of the Displacement Ventilation approach. In situ performance measurements from two buildings during the winter of 2008 are presented. Thermal comfort and air quality indicators are assessed and compared to the expected performance of the designed Displacement Ventilation system. Major discrepancies are highlighted and preliminary explanations are given in the light of the most recent considerations about this ventilation strategy.