Energy
efficient lighting design Energy
efficient lighting design The objective of a lighting design is to enable the user to perform a number of eye tasks with as less disturbance as possible. See L. Zonneveldt et al (156) and A. Slater (17). Due to the great variety in tasks in a modern office, task lighting by using daylight is difficult, especially in very turbid moderate climates (244). Although people are known to accept far more discomfort from daylight than from electric lighting the amount of daylight and the luminance distribution in the visual environment of the working person can only vary within certain limits; C. Bianchi & A. Georgescu (219). For electric lighting these limits have been very well established but a good system to describe the daylit environment remains to be a hot topic in lighting research, waiting to be elucidated.
An interesting view on how to proceed in lighting design was the paper on "a rational procedure for designing optimum lighting systems" contributed by Luciano Di Fraia (356). In this paper optimization computer software for carrying out an iterative calculation process through which optimum values for the number of luminaires, the utilization factor, and the maintenance factor of the installation is presented.
Another interesting contribution was the workshop on design by W.G. Julian (493); where special attention was drawn to interior finishing in relation to the combination of daylight and electric light. This workshop clearly demonstrated the importance of a careful assessment of the interior luminance distribution.
Laurens Zonneveldt et al (156) contributed an overview to the CIE TC3-24 of all aspects of energy efficient lighting design (156).
This basic model comprises a graphical representation showing the factors that influence energy flows in conjunction with lighting. The purpose of this model is to show on a conceptual level relevant processes and their interrelations in lighting design and application.
How all those factors are related can be found in the explanation of the basic model for energy and lighting.
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on the picture for more information
In this context also a method to compare the energy efficiency of different installations for the same room was presented. From a component oriented approach to system energy efficiency standardization the following formula has been derived :
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From this equation it reads that the energy performance of a complete set of appliances i.e. the combination of lamps, ballasts, luminaires, and control systems is considered. System energy efficiency and therefore running costs are usually less valued than investment costs, during decision making in the conception of a lighting design. This kind of somehow cripple desision making results from lack of a simple and adequate set of rules of comparison. It is here that the system energy efficiency equation presents a simple means to fulfill this demand.
An important contribution was the introduction of the ADELINE 2.0 package by Hans erhorn et al. (160, 216). This package comprises the lighting design programs Superlite and Radiance and comes with translators for popular CAD systems, its own modeller as well as interfaces with a number of thermal building simulation programs. Apart from ADELINE a number of other interesting tools were presented; D. Carter et al. (168), C. Suvagau et al. (221), Masayoshi Nagata (232), Minoru Isomura & Naotaka Ikemoto (236), Yoshihiko & Tetsuo Yamaya (238), Tashimoto Miyata (254).
