Fluctuating airflow thorough buildings is caused by temporal and spatial variations of wind-induced pressures around building envelopes, and include pulsating airflow and eddy penetrations. Two approaches using a multi-zone pulsating airflow model are introduced in this paper to study the eddy penetration and multi-way airflow through large openings. In the first approach, the eddy flow is considered to be caused by imperfect correlations among pressures at different points of an opening.

Multi-zone models are a common tool for calculating air and contaminant exchange within rooms of a building and between building and outdoors. Usually a whole room is then modelled by one calculation node with the assumption of homogeneously mixed conditions within this room whereas in real cases temperature and contaminant concentrations vary in space. The exchange to the neighbouring nodes via the flow paths is then a function of the local values of these variables.

The NORWEB Headquarters in Manchester, UK, is an air conditioned energy efficient office building of unusual design, completed in 1988. It has three stories with overhanging canopies providing solar shading and 21 % solar control glazing. The open plan interior is ventilated by a displacement system with three twist outlets in the floor to each desk position. A detailed questionnaire survey showed this to be one of the 'healthiest' buildings tested so far, with a very low 'building sickness symptom score'.