Daylighting and Energy Savings with Tubular Light Guides JITKA MOHELNIKOVA

Abstract:- Energy savings are actual tasks in many technical branches including the building industry. Buildings have to be design for low energy consumption. Energy savings in buildings can be achieved by reduction of energy consumption for heating, ventilation and artificial lighting. The design of build-ings with respect of solar radiation and daylighting gives possibility for energy efficient buildings. Saving of electric energy for permanent artificial lighting is important technical problem in internal parts in buildings without daylighting. Modern technologies have brought possibility to solve these problems. Tubular light guides are systems which serve for natural illumination of internal windowless parts of buildings. Their function is based on the principle of light transport from outdoor to distant in-door places due to multi-reflections on their high reflective internal surfaces. Advantage of these sys-tems is in the possibility of dynamic daylighting in internal parts of buildings and electric energy sav-ings for artificial lighting. Evaluation of indoor daylighting from a reference tubular light guide was completed. Light guides of different diameters and different light efficiency were compared with sources of artificial light. Energy saving for light guides of different efficiency was estimated