The question of the profitability of a lighting installation is always answered upon consideration of performance to be expected and resulting costs. The expectations in terms of performance, meaning photometric, visual and non-visual quality of lighting, are basically individual. With this in mind, it is advisable to attempt to describe costs and expenditure in relation to performance.
Since one of the most important quality criteria is illuminance in the visual task area, and the main cost factor in operation is energy consumption, it appears reasonable to consider the quotient of these two figures as an important parameter for lighting profitability. First, it is derived from the lighting installation’s connected load and the achieved illuminance without consideration of interfering light and dimmed operation. Energy efficiency can be enhanced by using light management.
Information on lighting energy consumption and potential savings with light management are provided in the chapter "German standard DIN V 18599". The influence of light management on light quality are discussed in chapter 8. A comparative cost calculation which can also factor in potential savings through light management is introduced in chapter 1.3.4.
Further aspects of lighting in the context of sustainable construction are outlined in chapter 188.8.131.52 "Building certification".