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					Information Sheet 166 (May 2000)


International Dark-Sky Association -- Information Sheet 166

ATM Lighting
How many people have not ever visited an ATM? Not very many. Some do so a lot. ATM's have become a staple of modern life. So most everyone has first hand experienced the various effects of "security lighting" in the vicinity of an ATM. It varies widely. In ATM lighting, there is the "Good," the "Bad," and the "Ugly." We discuss here some of these differences, and we will refer in some detail to the Illuminating Engineering Society of North America's Design Guide DG-9-97, which has the title: "Lighting for Automatic Teller Machines." The "Good" ones are those that are designed and installed following the IESNA's recommendations in their Design Guide. We quote in entirety the Introduction to the Design Guide: "The ATM environment requires adequate illuminance so users can perform reading and writing tasks, as well as enjoy safe passage to and from the ATM location. The customers' unrestricted access to ATMs means that proper lighting is a primary requirement during all hours of daylight and darkness. This guide will provide recommended illuminance levels, explain the need for glare control, and suggest methods to solve many ATM related lighting problems. Both the ATM lighting requirements for transaction processing and for safety are treated as major concerns." IDA thinks everyone would agree. Sections of the Design Guide are as follows: Introduction. Task, Equipment, Location. Lighting Objectives. Lighting Design Variables. Illuminance Criteria. 5.1 ATMs and the Immediate Surround. 5.2 Exterior ATM Approach Areas. 5.3 Minimizing Glare. 5.4 Avoiding Veiling Reflections. 5.5 Light Source Color Rendering. 6.0 Lighting System Choices. 7.0 Current Governmental Regulations. 8.0 Other Design Considerations. 9.0 Example Solutions 10.0 Conclusions 1.0 2.0 3.0 4.0 5.0

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Information Sheet 166 (May 2000)

Let us note especially Section 5.3, on glare, an important criteria often neglected. A quote from this section: "Direct visibility glare prevents the ATM customer from observing objects or an approaching perpetrator. Luminaires should be carefully selected and carefully located in order to minimize glare. Not all tasks at the ATM require the same level of illuminance, but uniformity is important if glare is to be kept to a minimum. Exterior lighting should blend from one area to the next, and the uniformity ratios should follow IESNA recommendations." So it is clear that ATMs that are "Good" have lighting levels that meet (but do not much exceed) the IESNA recommended lighting levels (if overlit, they will have too much contrast with adjacent areas, and likely will be glary), and they will have minimum glare. They will feel comfortable and safe to the customers. We quote also from Section 9.1, on Outdoor Solutions: "Large Approach Areas. If the approach to the ATM is across a large area (2.5 times the mounting height of the light fixtures or more), fixtures should be installed at the building (lighting outward) and at the approach perimeter (lighting inward). If the wall of the building where the ATM is installed allows fixtures to be at least 3.7 m (12 ft) above the ground, the light can adequately cover a length of 2.8 m (30 ft), with the exact dimensions depending on the light fixture and distribution pattern selected. Horizontal cut off type fixtures should be considered here because they can project the light without producing glare. For areas beyond 2.5 items the mounting height, use a pole mounted luminaire strategically located to illuminate the total area without interfering with the function of the space and normal movements. Important limitations [bolding as in the DG]: Avoid using luminaires which illuminate areas greater than 2.5 time their mounting height. These types of fixtures can produce excess vertical illuminance, which can result in direct disability glare. And where fixtures are installed at the building lighting outward, they typically create glare problems and contribute to light trespass." We note also that the new edition of the IESNA Lighting Handbook (9th edition) in the chapter on Security Lighting (Chapter 29) says: "Stray light from security lighting installations can be considered a light trespass by neighbors," and also "Disability glare is caused by light scattered in the eye. Care in the selection of luminaires and pole heights is essential." Now on to the "Bad." These installations arise from two major reasons. First, the owner of the ATM does not understand good lighting installations from bad, nor more generally what good lighting is. They often have only one goal: The More the Better. Second, the lighting "designer" has the same gap in their knowledge of good lighting, or if they do understand it, can not sell the advantages of good lighting to the owner. It is a sad fact that many lighting installations are built according to these perceived needs. No one questions the owners desire for an efficient, useful, and safe ATM installation. They just don't know how lighting relates to that goal. An even worse example of lighting specifications comes from state or local legislators, who have the same overall goals as the owners and also share the same sad lack of knowledge of lighting. For example, California Assembly Bill No. 244 includes a section on lighting of ATMs. This specifies a requirement of two candlefoot power within 50 feet of all unobstructed directions from the face of the ATM. There is no such unit as candlefoot power, but they define it in the bill as "the light intensity of candles on a horizontal plane at 36 inches above ground level and five feet in front of the area to be measured." Lighting with candles? Horizontal rather than vertical illuminance? Why 36 inches? Why five feet? And what is this non-existent lighting level unit?

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Information Sheet 166 (May 2000)

This sort of requirement has been copied or emulated by other states. For example. a 1995 State of New York bill says: "a minimum illuminance of two candlefoot power is maintained on a horizontal plane at a point fifty feet in all unobstructed directions from the ATM, measured at a point five feet above the ground surface." Candlefoot again. And who in the world will be looking on a horizontal plane five feet above the ground to benefit from this strange wording? How can state legislators or their lawyers or advisors come to such strange and counterproductive language? It boggles the mind, but these are existing lighting ordinances. There are no words about the quality of lighting, discomfort or disability glare. No understanding about the difference between horizontal or vertical illuminance. And where did candlefoot power come from? Now to the Ugly: These installations come from "designers" or installers trying to comply with either the owner's or the state's requirements. The lighting is normally mounted on the building wall, at what seems to be random mounting heights, often glaring right into the customer's eyes as they approach or use the ATM. Floodlights are projected horizontally to provide the required "candlefoot power" levels. This is the cheap and dirty and counterproductive way to do it. It should be avoided at all costs by any owners and any legislators seriously interested in protecting their customers and their facilities. We note also the recent Department of Justice report on crime and lighting, where it asks relative to ATM lighting: Who is being protected, the customer or the criminal?

Sound bites: Floodlight equals Glare Light. It costs no more in initial costs to do it right. Good lighting means real security and safety, bad lighting compromises both.

Reference: IESNA Design Guide DG-9-97, Lighting for Automated Teller Machines, prepared by the IESNA Financial Facilities Committee, copyrighted by the IESNA, 1997. IESNA, 120 Wall Street, New York NY 10005.

© IDA Inc., 3225 N. First Ave., Tucson, AZ 85719-2103 USA
Telephone: 1-520-293-3198 Fax: 520-293-3192 E-mail: Web:

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