Building Density and Interior Building Temperatures: A Physical Modeling Experiment

The effect of building density on the interior temperatures of buildings is explored using scaled physical models. The urban canopy layer is modeled as a single-cube structure surrounded by a wall that represents neighboring structures. Each physical model was constructed of plywood and consisted of a cube 200 mm in height, enclosed by a wall 200 mm in height. Four models were constructed corresponding to height/width ratios (H/W) of 4, 2, 1, and 0.5 and placed at an exposed site located at 34°N. The interior air temperature of each cube, direct and diffuse solar radiation on a horizontal surface, and ambient air temperature and wind velocity were measured over a period from late November 1996 to early June 1997. To extract the influence of building density, air temperatures were compared against those measured in the model representing a H/W of 1. The results show that nighttime cooling is primarily a function of building density, but that daytime heating depends on the interaction of density with changing model-sun relationships. [Key words: urban canopy layer, building air temperature, building density, physical model.]