The Effects of Luminaire Glass Type on Road Parameters in Road Lighting

The aim of this study is to draw attention to the light transmittance level of special glasses with low light transmission. Although it is known that the light transmittance of these special glasses is low, this study is important in terms of knowing the light transmission rate in question and what kind of light problems it causes in practice, because these special glasses can be used for road lighting in some special climatic conditions, for some experiments, or for the use of light in architectural designs. For this reason, it is important to know these special glasses light transmittance properties. As the light transmittance of the luminaire glasses increases, the amount of light on the road also increases. In other words, the light source or glass type affects the lighting performance of the road. The luminaire affects the light emitted from glass-type luminaires and reduces the luminous flux falling from the lamp to the road surface. For this reason, the lamp’s luminous flux with the appropriate power should be increased according to the light transmittance factor of the glasses. Otherwise, the conditions, specified in the CIE road lighting standards, cannot be met. For this purpose, luminaire glasses with different properties that can be used in road lighting were analysed according to their light transmittance of single glass (4 mm), double glass (4 mm), electrochromic glass (reflective), electrochromic glass (absorbent), and thermochromics glass. As a result, it has been determined that when the luminaires used in road lighting are without glass or the luminaire glasses are made of different materials, the lamps luminous fluxes should be increased according to the transmittance coefficient of the glasses.