Improving the quantitative features of architectural lighting at the design stage using the modified design algorithm

Abstract

Although there are some quantitative requirements, architectural lighting designs (floodlighting) as the only field of outdoor lighting have no dedicated design standards. These requirements are rather fragmentary and have the form of general recommendations rather than a detailed design standard, as it is for the other lighting applications. This arises from the fact that the most important objective of floodlighting is to make architecture looks more attractive at night. That is why, it is difficult to impose certain rules of objective quantitative parameters that could significantly limit the possibilities of creative shaping of aesthetic effects. At the same time, light pollution research has become very popular recently. The fact of illuminating an increasingly high number of architectural objects without quantitative control of the light pollution and energy efficiency issues can cause both electrical energy losses and a negative impact on the natural environment. This paper presents the concept of using a new system for quantitative assessment of floodlighting designs in the form of a new design algorithm. Its application allows us to minimise the energy loss from a given floodlighting installation and to reduce the environmental light pollution coming from it, with due care for the aesthetic effect achieved. By changing luminaires’ aiming and their dimming (using the control system), it is possible to increase the use of luminaires’ luminous flux, achieve the assumed average luminance level and not change the visual effect. Avoiding unnecessary oversizing of the average luminance positively affects light pollution from a given architectural lighting object and improves the energy efficiency of the designed lighting system. In the presented case, using a new design algorithm reduced light pollution by 79% and improved energy efficiency by 65%. The obtained results confirm the validity and the need to use the proposed changes in the design algorithm in practice