Dependence of the Light Transmission Coefficients of Multifunctional Glazing on the Angle of Incidence of Radiation

The operation of buildings with translucent facades increases the load on the heating and ventilation system due to transmission heat losses through the glazing, and on the air conditioning system due to possible overheating in summer. For this reason, glazing with sun protection, low-emissivity and multifunctional coatings is used in such facades. The characteristics of translucent enclosing structurers, as calculated according to normative documents, are taken into account when calculating the load on heating, ventilation and air conditioning systems, as well as when selecting the structures themselves in a given climate in order to save energy. In this case, the characteristics of the glazing were obtained in laboratory conditions when the radiation is perpendicular to the glazing, which is different from field conditions where the sun rays fall on the glazing at an angle. The available research works on the transmittance of solar radiation falling on glazing at an angle is based on laboratory studies, where various physical processes cannot be manifested and accounted for. Currently, research is being conducted in the Research Institute of Building Physics of the Russian Academy of Architecture and Construction Sciences to determine the empirical dependence of the light transmission coefficients of glazing with special coatings on the angle of incidence of the sun rays. The article presents part of the research and considers the determination of the light transmission coefficient of glazing with and without coatings from the angle of incidence of solar radiation.