This paper presents a generic equation which relates the Solar Factor variation with the incidence angle. The curves that result from this variation, for glasses and other transparent materials, were obtained through spectrophotometric experiments for transmission and reflection at different incidence angles. Groups of materials with similar variation behaviors according to the angle were identified. A reference material was defined for each group, representing the average behavior of the group. For these materials general equations of the Solar Factor variation curve were obtained, which allowed the calculation of the total heat gain, considering the change in the angle of radiation incidence over a period of time. The value of these gains for any material from the same group can be obtained by applying a correction coefficient, which is the Solar Factor value for the normal incidence of the material. In this study, those values are proposed for a large number of materials, or can be obtained from catalogs.
Transparent materials; Solar factor; Solar Heat Gain
