Abstract
The radiant heat transfer problems met with in buildings and urban spaces are complex and diverse, especially different depending on the inside or outside of buildings, because of the existence of atmospheric radiation in the outdoors, but the transparency in the rooms. To overcome such difficult problems and to get systematically understanding the whole problems, the radiant transport function is proposed. It is, in an endosure, defined as the responce at any point and any direction for the excitation of the radiant energy at a point and a direction by the delta function. The radiant transport function is transformed to the radiant transport factor, in the case when the boundary surface and the space are divided into some parts in which the radiant energy is uniform. The radiant transport function indicates the characteristics of the radiant energy transported in the enclosure. Therefore, it is effective for understanding the behaviour of radiant energy that the radiant transport function is obtained in buildings and urban spaces. The radiant energy is estimated simply integrating the function with the emissive power, otherwise tedeous calculations should be performed to solve the integral equation for the radiant transfer problem. The radiant transport function may be applied to the larger scale system of the heat transfer problem including heat convection and heat conduction and to the luminous transfer problem in the more complex room.
