ABSTRACT
Due to the fact that the investigated lighting system is not very common in practice and sets high financial demands, it was necessary to visit a large number of spaces where day light guidance systems have been installed to select the most universal implementations in terms of the defined boundary conditions and light guide structural designs used that will, at the same time, comply to the maximum possible extent with the regulations of the codes on which the boundary conditions are based. Out of all selected and measured rooms the one chosen for this presentation is located in the premises of the Institute of Geology of the Academy of Sciences of the Czech Republic in Prague 6 - Lysolaje. The selected room is situated on the first underground storey and serves as a library. The room is shaped like an orthogonal trapezoid 12.3(9.57) x
L. Janeþková & D. Bošová Faculty of Civil Engineering , Czech Technical University in Prague, Czech Republic
ABSTRACT: One for your healthy and full life needs natural light, which affects the biological rhythm of man. Design of daylight should therefore be well thought out, to arrange visual comfort for the user according to the predominant visual activity inside the room. Therefore we try to bring daylight into the interior to a sufficient extent and quality, through window openings or light guides, which must be designed not only to the adequate size, but also must be properly positioned. Quantitative criterion for day light is daylight factor D, which is expressed in percentage. Daylight factor D is defined as the ratio of daylight illumination at a given point of the plane E intr [lx] on the present outdoor illuminance levels E extr [ lx] for known or expected sky brightness distribution. Direct sunlight is excluded in both measurements. Quantitative criterion is the uniformity of daylighting r [-], which indicates the ratio between the maximum and minimum values of daylight factor. Another quantitative criterion is the distribution of light, preventing glare, light reflectivity and color of surfaces. With decreasing the possibilities of new construction are currently being used in less attractive locations for the construction and much more likely to approach various types of reconstruction. Reconstruction will help us as saving energy for heating or other aspects of improve interior, we must be careful to the negative influence of daylight inside a room. Also, existing dense development gives us a big limitation for appropriate design of the interior with the qualifying conditions for a visual activity. In places not directly neighbouring on the exterior environment a suitable means of lighting are daylight guidance systems which may transmit light over long distances. Their installation belongs to investments with high financial demands; therefore, adequate attention should be paid to the optimisation of their design with respect to the interior environment resulting in the maximum effectiveness of the designed installation even without any contact with the exterior environment.
