9.6 Lighting Layout
This part of the Energy Efficiency Manual shows how to lower lighting cost radically by efficient layout of lighting fixtures and by efficient distribution of light from the fixtures to the activities that require illumination. Especially in the design of lighting for new buildings, this aspect of lighting design holds more potential for reducing lighting cost than any other aspect of lighting.
Efficient lighting layout involves getting the light from the lamps to the task with a minimum of loss on the way, and delivering the light by paths that avoid visual problems. The lamp itself determines the initial direction of light emission. The light fixture, or luminaire, controls light distribution after the light leaves the lamp. The geometrical relationship between the fixtures and the activity areas is enormously important for lighting efficiency and for providing good visual quality. The surfaces of the space may be important also for controlling light distribution after light leaves the fixture. The energy conservation measures explained here cover all these aspects of lighting layout.
The powerful principle of task lighting is covered in detail. The advantages of task lighting are excellent visual quality, maximum energy efficiency, easy maintenance, adaptability, low initial cost, and independence from adjacent lighting, which allows independent control of the lighting of each activity area. You will learn the “standard” task lighting layout, which avoids glare, veiling reflections, uneven illumination, and excessive shadowing. At the same time, you will learn to address the challenges of task lighting, which is presently the least developed area of lighting design. To reach full potential, it requires major changes to present lighting design practice and innovations in lighting equipment.
Making the surfaces of spaces highly reflective is a powerful lighting efficiency principle. Here you will learn how to do it without causing visual problems.
Another technique you will learn is to install fixtures or combinations of fixtures that adapt efficiently to all modes of space usage. This is important for spaces such as meeting rooms, ballrooms, auditoriums, cafeterias, and restaurants.
The wiring of light circuits is an essential part of efficient layout. You will learn how to provide power to fixtures in efficient groups. To provide flexibility in grouping fixture operation, you will learn how to select and install programmable switches and lighting controllers.
The location of lighting controls is important because people will not use lighting efficiently unless control is easy and obvious. You will learn how to install controls in a way that motivates people to use them. For areas such as open office bays and factory floors, which have many individual work stations, pull-cord light switches can be an effective method of control.