Since most lighting upgrade projects are undertaken by the electrical contracting firm in design/build projects, it is important to establish measurable performance criteria for lighting upgrades. Lighting quality is subjective, and it is important that an electrical contracting firm base its lighting upgrade proposal, design, installation and commissioning on industry codes, standards and recommended practices.
Establishing measurable and verifiable performance criteria during the marketing stage lets the customer know that the proposed upgrade will meet current industry standard practices. At the end of the project, this assurance allows the electrical contractor to demonstrate to the customer that the system performs as promised.
Lighting quality criteria
The Illumination Engineering Society of North America (IESNA) establishes and promulgates standards and recommended practices for interior and exterior lighting. IESNA publications can be used to establish measurable criteria for lighting quality that range from the recommended maintained light level for a particular occupancy or activity to establishing a visual comfort level for individuals in a space. For example, the 10th edition of IESNA’s The Lighting Handbook (IES Handbook) includes criteria for establishing the needed horizontal and vertical maintained light levels for many common applications. Moreover, IESNA revised its previous recommended lighting levels to account for occupant age and recognizes that, as people age, less light reaches their retinas. The IES Handbook also provides information on lighting theory, artificial and natural light sources, luminaires, lighting design methods, controls, and specific lighting applications.
In addition, IESNA publishes recommended practices and design guides on specific topics. These publications range from designing for specific occupancies to more general guidance for systems. For example, IESNA RP-2-01, “Recommended Practice for Lighting Merchandise Areas: A Store Lighting Guide,” provides lighting strategies for retail spaces. This technical publication and additional educational resources are available at www.ies.org.
First and foremost, the design and installation of any lighting upgrade project needs to be in accordance with the edition of the National Electrical Code (NEC) adopted and enforced by the local authority having jurisdiction (AHJ) including any local amendments. Nowhere in the NEC are light levels mandated, but the articles in Chapters 1 through 4 apply to the installation of lighting systems. In particular, Article 410, Luminaires, Lampholders, and Lamps, and Article 411, Lighting Systems Operating at 30 Volts or Less, apply directly to lighting systems. Other important NEC articles that address lighting in hazardous locations can be found in Chapter 5 and Article 600, Electric Signs and Outline Lighting.
The NEC does not specify when emergency lighting is required in Article 700, Emergency Systems, or what light levels need to be maintained along paths of egress. The Code only specifies how to install, operate and maintain emergency lighting if it is required. Authorities having jurisdiction (AHJs) typically use NFPA 101, the Life Safety Code, to determine if emergency lighting is required, if light levels and uniformity must be maintained along paths of egress, and if any exit signage is required.
For exterior lighting, local requirements establish minimum luminaire photometrics to reduce light trespass and glare. Sky glow and nocturnal environmental impact must be considered. Care should also be taken to ensure that interior lighting does not violate local requirements for minimizing these effects through windows, skylights and other building fenestrations. Meeting local exterior lighting requirements can often be achieved by selecting an outdoor luminaire with the proper light distribution described by a rating system such as the backlight, uplight and glare rating system also known as the “BUG” rating system that is described in IESNA TM-15-07 Addendum A. Your distributors or lighting manufacturer representatives could help this process.
The National Electrical Contractors Association (NECA) publishes installation criteria for lighting systems called the National Electrical Installation Standards (NEIS). The installation standards that address lighting are typically co-sponsored by IESNA and are available through the NECA-NEIS website at www.neca-neis.org. The NEIS lighting standards encompass several types of lighting installations, including NECA/IESNA 500, Standard for Installing Indoor Lighting Systems, and NECA 501, Standard for Installing Fiber Optic Lighting Systems.
This article is the result of a research project, “Energy Roadmap: Electrical Contractor’s Guide for Expanding Into the Emerging Energy Market” sponsored by ELECTRI International, Inc. (EI). Thanks to EI for its support.
GLAVINICH is director of Architectural Engineering & Construction Programs and an associate professor in the Department of Civil, Environmental and Architectural Engineering at the University of Kansas. He can be reached at 785.864.3435 and firstname.lastname@example.org.