The observation of wind pressure acting on the wall and floor of a full-scale building model under cross ventilation was carried out. The measurement of air flow was also undertaken, and the existing prediction theory of the air flow rate, namely the orifice flow equation, including the discharge coefficient, was evaluated for its accuracy. At the same time, a method of predicting the discharge coefficient has been proposed and tested.
Water use is distributed throughout building structures. Energy used to pump the water to higher levels in the building is not currently recovered, and is dissipated by performing work on air in the ventilation system which is vented to the atmosphere, when the water is discharged into the drainage stack. This energy can be utilised productively, however, by strategically placing the air inlet for the drainage stack inside the building, thereby utilising the potential energy stored in the water to draw air through the building.
A study of the reliability of systems by considering the ability of different systems to maintain a required air flow rate over time is included in a subtask of IEA Annex 27 "Evaluation and Demonstration of Domestic Ventilation Systems". Measurements and calculations were performed to determine the variation in ventilation rates due to variation in climate and variation in performance of the ventilation system. Dwellings with passive stack, mechanical exhaust and mechanical exhaust-supply ventilation, representative of the Swedish housing stock, were studied.
The common way to determine air infiltration, exfiltration and interzonal flows from tracer gas measurements in multizoned buildings is to rely upon the standard single or multizone model, Vc(t) = Qc(t)+p(t) . Here c, p are zonal tracer concentrations and injections, t is time and V, Q are the sought volumes and flows. This model may work well provided that all zones are sufficiently well mixed and all flows really are constant during the measurements. The latter can be doubtful in naturally ventilated buildings, especially as the measurements may require several hours.
The problem of sensation of draught in ventilated spaces is connected to inappropriate velocities in the occupied zone. In Scandinavia, velocities higher than 0.15 m/s are said to be an indicator of that occupants are likely to feel discomfort. Therefore knowledge of the flow field (both mean velocities and fluctuations) is necessary. Both experimental and numerical analysis of the flow field in a full scale room ventilated by a slot inlet, with two inlet Reynolds numbers 2440 and 7110, have been carried out .
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