Energy saving lighting with light guides

Daylighting of internal parts in buildings an architectural and technical problem. Visual comfort in buildings is the main demand for quality of indoor environment that is superior even energy saving requirements. The windowless parts of buildings must have artificial lighting in a permanent service. Tubular light guide systems represent daylighting possibility and also energy saving alternative in a comparison with classical artificial lighting systems. The evaluation of internal illuminance from light guides of different dimensions and estimation of the light guides efficiency is presented in the paper.