Pressure Distributions Behind Double Facades the Implications for Natural Ventilation

摘要

Recent studies in the Boundary Layer Wind Tunnel at James Cook University, Townsville Australia, have pointed to unexpected (and currently undocumented) pressure distributions on the face of the building when the outer facade is sealed at the base, open at the top and there is free air movement over the face of the building between the building and the outer facade. When there is no double facade, wind that is blowing onto a building with an incident angle of 0°generates positive pressures on the windward face of the building and negative pressures on the leeward and side faces. As the incident angle increases these pressures change dramatically. However, when the same building model was shrouded with a double facade a steady negative suction pressure was recorded over all faces of the building. This continued despite changes in the wind's incident angle onto the building. This result was unexpected and has significant applications for hybrid and natural ventilation strategies for buildings. A review of the literature showed that this situation had not been recorded previously except for one reference to a similar situation by Cook on over cladding ' This paper outlines the research, presents the results, reviews this earlier study by Cook and presents the potentialimpact of this phenomenon for natural ventilation.