Nondimensional methods for natural ventilation design

The paper deals with the use of nondimensional graphs for designing the envelopes of naturally ventilated buildings. It is argued that such graphs offer several benefits over conventional procedures i.e. generality, ease and speed of use, wide application and accuracy. The graphs can be generated from theoretical models or from experimental data obtained from a direct measurement of ventilation rates in a wind tunnel model. Examples of graphs are given which cover conventional design conditions and, perhaps more importantly, off-design conditions. The off-design conditions include effects which would normally require a great deal of effort to calculate for a particular building e.g. the effects of adventitious leakage and wind turbulence. With the graphs described a designer can obtain a quick indication of whether such effects are important.