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Shedding light on security problems.

LIGHTING--A critical component of any security system--is more than a deterrent. It is essential to the effective operation of CCTV and security personnel. Without lighting, security officers cannot see and most CCTV is useless.

Lighting's positive effect on security is well documented. Consider the Fairmont Fair Mall in Camillus, NY. Customer visits to the mall were sagging even during a strong economy. Surveys indicated to the mall owners that much of the problem related to inadequate lighting in the parking lots.

The original lighting failed to illuminate areas where vandals could attack cars and property. It also created a glare that bothered drivers, pedestrians, and the mall's neighbors. After considerable expense, the mall parking lots were outfitted with new poles, luminaires, and lamps or bulbs.

While the energy savings were substantial, it seemed they alone would not pay back the mall owner's investment for 110 years. Nonetheless, payback was achieved in a few months.

The payback was greater shopper loyalty due to secure parking lots. This in turn brought the mall more sales, higher rents, and lower vacancy rates. Vandalism dropped to near zero, and the increase in security allowed the mall to reduce its uniformed security personnel.

Building owners and security managers often view security lighting and other security measures as budget drains. Unfortunately, that way of thinking keeps security lighting from achieving its full potential. Security managers must convince building owners that the benefits of upgraded lighting systems go beyond prevention and deterrence of crime. While an investment may be required, the benefits--including liability avoidance--can result in fast paybacks.

SECURITY MANAGERS MUST CAREFULLY consider various elements in security lighting systems and how they interrelate. The key elements in a system are lamps, luminaires, ballasts, maintenance, and controls.

Lamps. Commonly referred to as bulbs or tubes, lamps produce the light that helps create security. Finding the right lamp is imperative. Some units may be expensive but ineffective. Six families of lamps are commonly used in lighting systems today: incandescent, fluorescent, mercury vapor, metal halide, high-pressure sodium, and low-pressure sodium.

Incandescent lamps are the oldest family of lamps. They work when an internal filament is heated to glowing, thus emitting light and a great deal of heat. Almost 90 percent of the energy that goes to an incandescent lamp creates heat rather than light.

The other families of lamps are much newer, and all require a ballast to work. The electrical charge is modified through the ballast to excite gasses within these lamps, thus emitting light. Fluorescent, mercury vapor, metal halide, high-pressure sodium, and low-pressure sodium lamps all work basically this way but for differences in the way they are designed and the types of gasses used.

Security managers should compare each lamp's efficiency in terms of lumens (light output) per watt (power required to operate it). Managers should also consider a lamp's lumen depreciation. After initial burn-in, which is the initial phase of the lamp's light when the metal parts are heated to glowing for the first time, the light output of lamps slowly diminishes while still requiring the same amount of electricity to work. As a lamp ages, it becomes less efficient.

Security managers must look at the current system's components before upgrading a lamp. Many outdoor lighting security systems depend on mercury vapor lamps. While these were once state-of-the-art, today other choices can do the job better for less.

Incandescents are also commonly used for security purposes because they are inexpensive. Unfortunately, incandescents are among the least efficient and shortest-lived lamps. This makes them expensive and unreliable in the long run. A security system depending on incandescent lighting should be retrofitted with halogen lamps.

Halogens are incandescents, but they are markedly more efficient and work well outdoors. Halogen refers to the halogen gas in the bulb that helps it emit more light or energy. This whiter light lasts longer. Manufacturers are improving their halogen parabolic aluminized reflector (PAR) lamps with new models that are smaller and increase brightness. Halogen spotlights are excellent for directing light toward certain areas because the beam control is better.

Low-pressure sodium, high-pressure sodium, and metal halide are the best lamps for long life and efficiency. The choice of which to use depends on the situation. For instance, low-pressure sodium lamps can last up to 18,000 hours with virtually no light depreciation, but their light turns everything gray. Low-pressure sodium lamps used in a parking lot make everything look as if it is a black-and-white movie.

High-pressure sodium lamps produce a golden white light and last up to 24,000 hours. Metal halide lamps, through new processes and coatings, can closely approximate the high quality light of incandescent lamps while lasting almost 20,000 hours.

Most models of these three lamp types take several minutes to warm up before attaining full light output. If they are ever accidentally turned off, it may take some time before they restart because the lamp must cool first before relighting.

Luminaires. Luminaires house the lamps that produce the light. While this may seem a simple enough function, mismatching luminaires to lamps can seriously impair a highly efficient lamp. Luminaires can be efficient or not regardless of the lamp installed as indicated by a coefficient of utilization (CU) rating.

CU is determined by the ratio between a fixture's light output and the output of lamps alone. For example, a luminaire that produces 40,000 lumens when fitted with a lamp that produces 60,000 lumens is 67 percent efficient. The other 33 percent of light is absorbed by the luminaire's surface or is trapped inside. CUs are assigned to luminaires by the manufacturer using standardized procedures.

Many durable and tamperproof luminaires are on the market. These security luminaires may cost more than standard luminaires, however, cost savings can be eaten up in replacement lenses and lamps.

Outdoor security lighting systems can create problems if improperly designed. For instance, light trespass can be a problem. As shown in Exhibit 2, this occurs when poorly designed outdoor security lighting "trespasses" onto adjacent properties. Security managers should ensure design of a lighting system with attention to where the light goes off the property as well as on it.

Much of today's security lighting is based on pole-mounted, outdoor luminaires. The following basic luminaire types are available:

Cut off. This luminaire reduces direct glare on areas of surveillance and is good for medium- to wide-range parking areas and security areas directly adjacent to residential neighborhoods.

Refractor. A wide beam emanates from this luminaire with little control over spill light. It is most effective on highways or other areas where trespassing light is a less important factor than wide pole placement.

Low-mounted site. On the opposite end of the spectrum, these luminaires are used where small areas must be lighted with a minimum of glare and trespass. Variants include bollard types that hide the lamp to "downlight" models. Downlight means light directed downward.

Post-top (uncontrolled). While decorative, this luminaire may waste light above the horizontal, the area from the top of the lighting plane up to the sky. Light in this area is generally wasted.

Post-top (controlled). Also decorative, this luminaire is more efficient due to better light control and distribution. It is used principally for walkways, site lighting, and small- to medium-size area lighting.

High-mast. This versatile high-wattage luminaire is for large area lighting. The high-mast can hold up to six luminaires with excellent control of direct lamp glare.

Floodlight or projector (full cut-off). Where control of light is critical, such as airports or areas immediately adjacent to residential areas, this luminaire cuts off light on the upper portion of the vertical beam. In other words, it keeps light below the horizontal.

Floodlight or projector (semicut-off). This luminaire is used where control of light trespass is important. It uses louvers and medium- to high-wattage lamps.

Building mounted (refractor type). This all-purpose, low-wattage luminaire simply lights areas around buildings but might be objectionable in many areas due to light trespass.

Building-mounted (cut-off type). For more light trespass control, this luminaire uses a reflector to control the upper beam spread.

Floodlight or projector (noncut-off). This type of luminaire uses medium- to high-wattage floodlights for a tight, symmetrical beam control. Wide to narrow beam spreads are available, and the unit is normally used where a long throw of light is more important than controlling light trespass.

Ballasts. Ballasts are a part of security lighting that deserve close attention. A ballast modifies incoming voltage. It also controls current and provides the conditions necessary to start and operate electric discharge lamps--all those families of lamps except incandescent. Most ballasted lighting installations are fluorescent. Electromagnetic ballasts and electronic ballasts have pushed the life expectancy and energy efficiency of ballasts up to the point where retrofit is a cost-effective option.

Security managers must closely look at outdoor lighting that involves metal halide, high-pressure sodium, and low-pressure sodium lamps. The ballasts for these are specific and usually cannot be interchanged with other types of lighting. For this reason, retrofitting becomes an option only when the lamps involved are relatively new or when high-power rates in the area make the change of equipment cost-effective.

If a security lighting system is more than five years old, however, it pays to look for ways to upgrade the ballast system because the manufacturers have made such strides in efficiency and longevity.

Cost factors are important if the security lighting system is being designed from scratch. These cost factors gain significance when comparing competing technologies rather than competing equipment. In other words, ballast cost is a consideration when comparing a metal halide system to high-pressure sodium or when comparing high-pressure sodium systems of differing wattages.

Security managers should keep in mind which of the competing technologies serves the company's purpose. Switching later will be costly. Switching from 300-watt to 750-watt high-pressure sodium is simpler and less costly, however, because the same ballast is used.

Maintenance. A major facet of security lighting involves mounting luminaires high above the affected area. While pole and mounting technology have not taken any giant leaps in recent years, the maintenance process has.

The expense of maintaining lights that sit 50 feet in the air was once a major concern to property owners. Now lighting maintenance companies can keep out-of-reach lighting working to its fullest capacity at a low cost.

Maintenance is a growing force in the lighting field. Proper maintenance keeps lighting systems functioning at their peak, which enhances security and saves money.

Lighting fixtures and lamps tend to attract dirt, especially when located outdoors. This dirt buildup soaks up light and degrades the performance of the luminaire. Regularly scheduled maintenance allows a lighting system to work at its fullest capacity.

"Group relamping" is another growing trend in lighting maintenance. Often, lamps are replaced as they burn out. Unfortunately, this practice wastes time, money, and energy. Group relamping allows the maintenance crew to assemble all the equipment necessary to relamp the whole system at once. In addition, group relamping allows for better quality light because lamps are removed before they degrade to the point where they barely operate.

Consider exhibit 1 again. Manufacturers assign a rated life number to each lamp they sell. This rated life represents the point at which half of a large group of test lamps fails. Replacing lamps just before that point keeps light levels high enough to ensure the security the lighting system was designed to maintain.

Controls. Controls are the means by which lights are turned on and off or dimmed. The many possibilities of controls are still being investigated by lighting manufacturers. Even the current products on the market however, are space-age in their applications.

The latest technology is microprocessor-based, centralized, programmable lighting control. Although designed principally for lighting, this new method is capable of handling other loads, such as HVAC, computers, and water pumps. The system can be upgraded by integrating photocells and split-ballasting controls. Split-ballasting is when two lamps share the same ballast.

Microprocessor-based programmable controllers can be integrated into the company's networked lighting control systems. These systems allow schedules and other programmable functions to be entered into the system and then modified from a central operator console.

Networked systems also allow input from various sensing devices, such as master switches, photocells, occupancy sensors, telephones, or load-shed contacts to control relays or dimmers, thus reducing the wiring needed in configuration.

Lighting moves from being a security enhancement to a security tool in buildings with occupancy sensors. These high-tech devices detect motion in a space and turn lights on accordingly. When security personnel see lights going on in the building after hours, they know an intruder is present, and they can take action immediately.

Occupancy sensors operate via ultrasonic or infrared technology. They are also good energy-management tools. By ensuring that lights are turned off when rooms are empty, occupancy sensors save energy and increase lamp life while enhancing long term security.

Photocells are not a new technology but are still cutting edge as far as security and energy efficiency are concerned. Photocells ensure that a certain level of light is maintained in a given area at all times. For instance, on an overcast day, security personnel may need extra light to maintain visibility.

As security concerns grow, lighting technology continues to advance to meet new demands. If a lighting system is five or more years old, it should be examined in light of new demands and system capabilities to determine if the company is getting the most security from its lighting dollar.

Bob Jefferson is an editor, technical writer, and account executive for Construction Industry Technology Inc. of Silver Spring, MD, which performs research for the National Lighting Bureau.
COPYRIGHT 1992 American Society for Industrial Security
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1992 Gale, Cengage Learning. All rights reserved.

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Title Annotation:security lighting systems
Author:Jefferson, Bob
Publication:Security Management
Date:Dec 1, 1992
Words:2279
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