Influence of Building Envelope Type on the Minimum Mechanical Ventilation Rate to Achieve a Positive Indoor Air Pressure

Abstract

In order to limit the infiltration of outdoor air pollutants, a positive indoor air pressure should be maintained. This study aims to investigate the minimum mechanical ventilation rate to achieve a positive indoor air pressure for large space buildings with different kinds of envelopes. The types of building envelope include envelope with multilayer windows (which generally appears in shopping malls and open-plan office buildings), envelope with entrances on the first floor and multilayer windows, and envelope with openings at bottom and top levels (which generally appears in industrial plants). It is concluded that the minimum ratio between mechanical ventilation and initial infiltration rates to achieve a positive indoor air pressure depends on the window width-height ratio, the vertical spacing between windows, and the number of window layers. More regulations are summarized and analysed to guide the ventilation design.