For industrial applications, the lighting designer must consider a variety of factors including user needs and preferences, safety regulations, maintenance requirements and energy consumption.

Analysis of the Industrial Space
One important aspect of design is a detailed analysis of the interior environment of the industrial space. Functional elements that impact lighting design and effect the overall light delivered to the task include ceiling height, room surface finishes, windows, skylights or other fenestrations, and the geometry of the space. Environmental conditions, including dust and dirt, moisture, wet locations, hose-down areas, insects, temperature extremes, vibration and incidental abuse have a significant effect on the selection of the proper luminaire. Food processing areas, for example, sometimes require special options for lighting fixtures.

Exterior spaces also require evaluation. Lighting can enhance the architectural features of a building at night and also provide safety and security as it directs people to entrances. General exterior considerations include the type and color of exterior building materials, type and location of plants used in the landscape, and the placement of exterior lighting so it does not interfere with driveways or produce glare.

Lighting renovations should consider the same design criteria as new construction, as well as issues of existing wiring, changes in task locations, and removal of hazardous wastes.

Evaluation of Psychological Aspects
Employee attitude can have a dramatic impact on productivity. While the lighting designer cannot address all related issues, effective lighting design can have a positive impact. Proper lighting can increase employee comfort with the effective use of colors, contrast, and luminance. Control of glare can reduce visual fatigue.

Requirements for Flexibility in Lighting
In today’s dynamic environment, changes in the workplace often require general renovations. If the location of assembly lines or storage racks changes, the lighting must be re-evaluated. In applications where task locations change frequently, the use of flexible wiring systems may offer significant advantages. Initial installation time will be reduced, and relocating luminaires in the future becomes much easier and more cost-effective.

Task requirements may also change throughout the day. Manufacturing activities may be conducted during one shift, maintenance of equipment performed during another shift, and security may be necessary during the non-productive periods.  Lighting needs will vary, therefore automatic on/off switching and or dimming controls may be beneficial.

Safety Requirements
Light levels must be sufficient to minimize on-the-job injuries which occur more frequently in industrial settings. Of particular interest is the stroboscopic effect, a condition in which rotating machinery appears to stand still because it operates at the same frequency (60 cycles per second) as electric current.  Stroboscopic effect can be eliminated with fluorescent electronic ballasts, which operate at higher frequencies – 20,000 cycles per second and higher – or by connecting adjacent fixtures to different phases of three-phase electrical distribution systems. In addition, well designed lighting can also minimize damage to machinery and inventory which reduces overall costs and may lower insurance rates.

Lighting must also ensure a safe environment during an emergency. In the event of a fire or power outage, emergency lighting and exit signs must enable occupants to identify a clear path of egress, even through smoke.

Installation and Maintenance Requirements
Installation and maintenance requirements can be important considerations when choosing industrial lighting system. In many cases, industrial luminaires are mounted at high elevations, directly over machinery, or in locations where special equipment is required to access the luminaire. Choose components that minimize labor requirements such as long life lamps and quick-connect modular wiring. With modular wiring, fixture installation is accomplished in a fraction of the time it takes for conventional hardwiring, and fixture relocation is fast and easy.

Building and Electrical Codes
Many states, provinces and regions have enacted energy code for local building construction. Also, as a result of the Energy Policy Act 1992 (EPACT), all states are required to meet minimum energy requirements as specified in the ASHRAE / IESNA Standard 90.1 1999 code. Standard 90.1 establishes watts-per-square-foot criteria for various types of applications. Among other factors to be considered are the requirements of the Americans with Disabilities Act which provides guidelines and specifications for barrier-free environments.

Energy Requirements
Lighting is a primary energy component for industrial applications. Careful consideration of the lighting energy-use can have a substantial impact on operating costs. Design criteria should evaluate the local energy rate, lighting usage requirements throughout the day, and the availability of energy saving technologies. Control systems such as motion sensors, daylighting sensors, time of day controls and energy management systems can further reduce energy consumption.

To help designers evaluate the energy efficiency of luminaires, a metric called Luminaire Efficacy Rating (LER) is used. This metric describes the luminaire’s delivered light output compared to the energy input – or lumens per watt. The National Electrical Manufacturer’s Association has developed guidelines for LER values for industrial fluorescent and high-intensity discharge luminaires1.

The US Environmental Protection Agency (EPA) promotes two programs that emphasize energy efficient lighting systems.

Green Lights is a voluntary pollution prevention program. By joining Green Lights, partners agree to install energy efficient lighting where profitable as long as lighting quality is maintained or improved. Lithonia actively participates in this program as a Green Lights Ally.

The ENER Buildings program is another voluntary energy-efficiency program. It focuses on overall load reductions for building systems including lighting, heating, ventilation, air-conditioning, motors, and fans. Partners can expect to reduce total building energy consumption by 30% on average. Internal rates of return (IRR) range from 17% to 50%. Lithonia Lighting is proud to have received the Energy Star Exit Sign Partner of the Year award in 1998 and 1999 for outstanding product and services for Exit Lighting.

Cost Considerations
The overall cost of the lighting system depends on a number of variables: the initial cost to purchase and install the system, the costs associated with operation and maintenance, and the energy required to operate the lighting. Energy is the most significant overall cost for lighting. Small incremental costs in purchasing energy-saving components are paid back quickly with the operating savings. Premium materials may increase initial capital costs as well, but offer such advantages as superior color rendition, better maintenance, and lower operating costs.

It is also important to consider the financial benefits that result from high quality lighting: improved productivity, lower rejection rates, better quality control, and increased customer satisfaction. According to the National Lighting Bureau², high quality lighting has been shown to reduce rejection rates by 25 percent or more.

1.National Electrical Manufacturers Association Standard Publication No. LE5 – 1993, "Procedure for Determining Luminaire Efficacy Ratings for Fluorescent Luminaires" and Publication No. LE5B – 1998 "Procedure for Determining Luminaire Efficacy Ratings for High Intensity Discharge Industrial Luminaires" (publication pending)

2.National Lighting Bureau, "The NLB Guide to Industrial Lighting", 1992