Lighting and Design Goals
When people can see better, they work better.
A typical industrial facility houses many people engaged in a wide variety of visual tasks. The task may be small, such as assembling a circuit board, or large, like operating a smelting furnace. Tasks may involve movement of objects, the viewer, or both.  Well designed lighting systems can make a direct contribution to the success of the operation. They can enhance form and function, enhance workers’ visual comfort, improve safety and security and create flexible spaces that adapt to the task at hand. Unfortunately, lighting it is often treated as an afterthought during the initial building design phase.  More attention is given to the physical dimensions of the production floor, process and production flow and equipment.     
Providing successful lighting systems for today’s industrial facilities is a complex task, requiring a wide breadth of experience and knowledge on the part of the designer.  Specific requirements will vary depending on the type of industry and location of production processes and buildings within a large complex.
The general design considerations for industrial lighting are:
1.  Determine quality of illumination for the process involved.
  • This involves how light is distributed and directed within the visual environment.
  • The light must contribute to visual performance visual comfort, ease of seeing and safety for the visual task.
  • Direct glare, luminance and luminance rations, reflections, distribution diffusion and shadows, modeling of 3D objects, reflected glare, flicker and strobe, source/task/eye geometry, diffusion and shadows, uniformity and color quality of light, all have an effect on visibility and the ability to see tasks accurately
  • While daylight can be used to help light an industrial space the quantity and distribution and associated heat gain must be controlled
2.  Determine the quantity of illumination for the process involved.
  • Quantity of light (illuminance) depends upon seeing task, the worker and the speed and accuracy in performing the task
  • Tasks may be horizontal, inclined, or vertical
  • A classification of industrial tasks from simple to complex and the recommended illuminance levels for these tasks are provided in the IESNA Recommended Practice for Lighting Industrial Facilities.  Typical illuminance levels are: 50-65 foot candles for manufacturing and 10 – 3- foot candles for warehouses.
3.  Select the light sources and luminaires that meet quality and quantity requirements in regards to:
  • Photometric characteristics
  • Color rendering characteristics. Satisfactory CRI for non-important tasks is >20, important tasks >70 and critical tasks >85
  • Lamp type. A wide range of fluorescent lamps are available with different color temperatures, color rendering and life. The range of HID lamps is more limited. Point source and linear placed LED luminaires are instant on, dimmable, long life and offer the greatest energy savings.
  • Mechanical performance that will satisfy installation, maintenance and operating conditions of the work environment
4.  Place the lighting equipment that will be easy to maintain.
  • Different lighting choices will influence the number of luminaires you require and the quality and uniformity of the light. In general, point sources require fewer luminaires but result in more shadows, whereas linear arranged luminaires will give more uniform light but require more luminaires.
  • Most industrial applications call for direct or semi-direct luminaires, either fluorescent or HID. The upward component of semi direct types illuminates the ceilings and upper structures to help reduce luminance ratios between luminaires and the background (i.e. the “dungeon” effect associated with direct luminaires)
  • Other equipment considerations:
    • Light colored finishes on the outside of luminaires reduce luminance ratios between the light source and the outside surfaces
    • Higher mounting heights keep luminaires out of the normal field of view
  • Luminaires may require shielding of light using deep reflectors, cross baffles or louvers. (e.g. T5 HO and HID light sources)
  • Difficult visual tasks may require supplementary lighting, from fixed or portable luminaires
5.  Compare the energy management considerations and initial cost of equipment, management of spent lamps, disposal regulations, use of TCLP compliant products, against the quality and quantity requirements for optimal visual performance
These and many other lighting design considerations, are covered in greater detail in the IES Recommended Practice for Lighting Industrial Facilities.