Shedding Some Light On Security

Aug. 5, 2002
Outdoor Lighting Isn’t Just Smart – It’s Safe
If your security strategy involves card readers and guards, you’re off to a good start. However, there may be one component of effective security that you’ve neglected to evaluate – outdoor lighting. It’s no secret that properly lit outdoor environments provide a perceived level of safety to individuals and deter criminals from illegal acts. Putting together a plan for effective area lighting can be overwhelming if you don’t understand the basics.Identification vs. RecognitionThe right outdoor lighting plan can mean the difference between identifying an individual and recognizing them as a potential perpetrator. The goal is to provide enough light so that people can see not only shadows, but faces and colors. Selecting the right lamp is a key part of building a good plan. The following are popular choices:High Pressure Sodium lamps are more efficacious (meaning they emit more lumens per watt) than metal halide lamps. However, as Eric Jensen, manager of Application Engineering, Lithonia Lighting, Conyers, GA, points out, “HPS lamps are only good where the color of anything lit by the luminaire is a non-issue.”Metal Halide lamps are rapidly becoming the product of choice. These lamps provide improved color rendering over HPS lamps. “Relating to security, often the white light of metal halide is more preferable, particularly in a commercial establishment,” says Anthony W. Burns, manager of marketing programs, GE Lighting Systems Inc., Hendersonville, NC.Pulse Start Metal Halide lamps achieve quicker cold start and more rapid, hot restrike than metal halide lamps. “A lot of the pulse start lamp manufacturers are providing lamps that have less lamp-to-lamp color variation and less color variation over the life of the lamp,” adds Mike Krueger, technical services manager, Ruud Lighting Inc., Racine, WI. “They also incorporate a little higher lumen output, so it’s a more efficient source [than metal halide].” Vertical illumination is another means by which recognition is achieved. “You can measure footcandles either horizontally or vertically. If you were to look straight at somebody’s face, the amount of light that is hitting them in a vertical fashion is what is going to determine how well you recognize who that is,” says Patrick Walker, marketing manager, McGraw-Edison, Cooper Lighting, Peachtree City, GA. Walker recommends using fixtures that emit light in a direction in order to to give off high levels of vertical illumination. However, he warns that if you provide high vertical illumination above 70 to 75 degrees, you will create glare, and consequently contradict the goal of providing a secure environment. “The person that is walking out into the parking lot is going to be blinded by that intense light source … and that gives the opportunity for an assailant to do something,” Walker notes. Preventing glare and creating a uniformly lit outdoor environment increases safety, recognition, and security.Lights, Camera, ActionIt’s important to see lighting as part of an integrated security plan. The reasoning behind this philosophy is simple: If you install outdoor lamps and fixtures that prohibit the ability of your security cameras to record activity, then the plan has been compromised. “Having the right kind of light for your surveillance cameras is important. It allows you to detect and identify,” stresses Burns.Carefully investigate what type of lighting will optimize the performance of your camera(s). “Lighting for security cameras is completely a function of the capabilities of the particular camera used. Three big issues are: maximum to minimum ratio since the camera has a finite dynamic range; minimum light level since there is a low-end threshold at which the CCD can detect light; and proper aiming of the lighting such that the objects are well lit vertically,” Jensen explains. The question of how to keep pathways and egress points lit during a power outage may have a more simple answer than you think. Some new regulations are citing the need to provide at least one footcandle of light on pathways extending out to the parking lot. In response to these requirements, manufacturers have provided two solutions. According to Walker, “You can put in certain fixtures, a battery pack, and a fluorescent light such that if the power completely goes off, you’ll have that battery pack to equip the fluorescent lamp and maintain the emergency light levels you need for people to safely exit your building.”Your second alternative is to wire an auxiliary quartz lamp within the fixture to separate circuits. “It’s not uncommon to have an emergency generator that is wired to your emergency lights, and it can therefore also be wired to your outdoor lights,” Walker confirms.Finding the Right Fixture(s)
While certain levels of seemingly excessive light can create perceived safety, the most basic of guidelines include avoiding glare, light trespass, light pollution, and providing uniform light distribution. Selecting the appropriate luminaires will affect your ability to achieve these goals. “There is a move toward flat glass, which causes less glare,” says Walker. “Unfortunately, it usually causes more fixtures to be used in a parking lot and so power and wattage consumption goes up and glare goes down.” Despite the inherent benefits, using only what the Tucson, AZ-based International Dark-Sky Association has deemed as “full cut-off” fixtures in outdoor lighting design is still somewhat of a controversial idea. Additional ways to reduce glare involve carefully aiming flood lights, installing glare shields, and mounting fixtures at appropriate heights. “You can provide a safe environment or a lack of glare if you’re utilizing and incorporating the right wattage at the right height. If you put too high of a wattage fixture at too low of a mounting height, it’s uncomfortable,” Krueger adds.During a security audit and closer evaluation of a facility’s outdoor lighting needs, determine the likelihood of fixture damage. If vandalism is a concern, opt for products that are bullet-resistant or use tamper-resistant hardware. In areas where fixtures are likely to suffer abuse, invest in more durable products. “Heavy-duty, corrosion-resistant fixtures that properly seal out insects and moisture are well worth the initial investment. Even a gardener’s lawnmower can virtually demolish a poorly made floodlight,” stresses Burns. Penetration of insects in addition to damage from vandals and weather can degrade the amount of illumination necessary for building a safe and secure outdoor environment.Most lighting manufacturers provide an applications service to assist you in making the right decisions about lamp and fixture selection, as well as lighting design. Provide CAD drawings of your parking lot or outdoor area and get assistance from the experts. “We’ll generate a layout for you, showing you what the light levels are, showing you what the uniformity is, and showing what fixtures we use and its total power consumption. That’s an easy tool for a … building manager that might want to retrofit – and it’s free of charge,” says Walker.With these bright ideas in security, it’s no wonder that good lighting is getting easier – and safer.Jana J. Madsen ([email protected]) is senior editor at Buildings magazine.

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