Field Investigation on Heat Transfer in an Urban Canyon

Field measurements of the heat transfer in an east-west oriented urban canyon are performed in the summer and the winter seasons, as preliminary research of the heat transfer in the urban surface boundary layer. The canyon is made of concrete buildings (16 m in height) covered with windows, standing face to face across an asphalt road (17 m in width). The heat transfer in the urban canyon is represented by the energy balance at the imaginary surface named “the top surface”, which is the plane above the canyon at the same level as the roof surface. The net amount of the transferred heat into the urban canyon is more than four times greater than that into the roof, and reaches about 50% of the net radiation heat transfer on a summer day regardless of the meterological conditions. In the daytime, there is no significant difference in the convective heat transfer between the roof surface and the top surface.