Whether you’re selecting fixtures yourself or working with a specifier who decides and approves fixtures, the more you know about lighting fixture selection the better. Armed with this valuable information you’ll be able to ensure the lighting choice best meets the needs of the project and complete the job on time, while maintaining your profitability. This is particularly true if you’re a contractor who works on design-build projects. Your fixture knowledge can help you respond to changes in design and fixture specifications and resolve conflicts. Less indecision or conflicts means less time off the job and more profitability. Keep the following information in mind when selecting building security and emergency lighting fixtures.

The heart of effective lighting selection is knowing which fixtures produce the light needed for various applications around a building. To do that, you need to be familiar with fixture optical characteristics, lamps, housings and mountings.

Remember that the overall goal of security lighting is to protect people and property, usually from dusk to dawn. Security lights help to discourage unauthorized entry, property damage and personal attacks. To achieve that, the fixtures need to uniformly illuminate the perimeter of a building with defined beams of light. In addition, security fixtures should produce a high contrast in light levels between a potential intruder and the background.

Overall Considerations

The first step in selecting appropriate security fixtures for an application is to evaluate the building’s exterior and environment. Take into account the building’s use, size, exterior, sidewalk, pathways, barriers, fences, parking lot and neighboring structures. Know the required light levels for the type of building as specified by local ordinances and codes. Be aware of the property lines and surrounding light levels and how nearby lighting effects the building’s area light levels. Then select the fixture’s reflector and optical system characteristics to create the best beam pattern coverage to light each perimeter area. Avoid placing too many fixtures, but always maintain adequate light levels. Don’t compromise safety by placing fixtures too far apart.

Various building-, pole- and ground-mounted fixtures are used to illuminate the area (usually a minimum of 20 feet out) around a building. Security fixtures can include wall packs, area lights and bollard type fixtures. Surface mount fixtures are used to produce downlight, uplight, wall washing, lateral and forward throw light on the side of a building or areas immediately below or beside it, such as a walkway. Pole-mounted fixtures light perimeter areas, sidewalks and parking areas near a building. Bollard-type fixtures light sidewalks and pathways near building perimeters.

Select fixtures with the proper beam pattern and cutoff to reduce disabling glare, light pollution and spill light onto adjacent properties. Using fixtures with full, cutoff or semi-cutoff optical characteristics helps reduce light pollution and spill light. Pick fixtures that are easy to aim and have accessories that help reduce glare or light pollution. A white translucent lens diffuses light evenly and controls glare. Shrouds and louvers help control glare as well. Some fixtures offer optional louvers installed behind the lens to prevent damage. Also consider selecting fixtures with photo cell control for dusk to dawn lighting or infrared or motion sensors to activate a fixture’s lamp only when needed. These controls also help save energy.

Fixture Optical System Types

This circular-shaped fixture lends aesthetic appeal to this wall application by providing wall wash and a grazing effect to highlight the wall’s texture.

Following are fixtures used for security lighting and their optical system types and characteristics.

Ceiling Mount :

Cutoff: shrouded on all sides, offering symmetrical controlled downlight and effective, even light distribution.

Cutoff with up/down lighting: shrouded on all sides with controlled uplight cutoff to shine on ceiling as well as downward in a wide, uniform beam pattern. This fixture provides safety and creates a safer feeling environment in areas with low ceilings. A fixture with uplight is also effective in lighting a window area or above a door.

Wall Mount:

Perimeter or Lateral Cutoff : provides wall washing, lateral and forward throw light distribution to light the side of a building and areas immediately beside it, such as a walkway. A 90-degree cutoff feature helps prevent glare and light pollution.

Projection Cutoff : projects light down, out and away from the fixture to illuminate areas such as small parking lots or areas next to buildings.

Deep Shielded : full lateral and downlight in controlled distribution that helps prevent glare and spill light. This fixture is ideal for entryways and other areas where avoiding source brightness is important.

Forward Throw : throws light out on an area away from a building such as a parking lot.

Lamp Type

To select fixture lamps, be aware of the range of lamp wattages and types available for each fixture. Note that a fixture’s size or design could restrict the lamp wattage or type. Choose the wattage that produces the right amount of light for each application. For example, a surface mount fixture mounted 15 feet above the ground on the side of a building could use a 150 watt metal halide lamp to light an entrance area. Consult the lighting fixture manufacturer’s isofootcandle plot and candlepower distribution curve to make sure the fixture with a particular lamp type and wattage will effectively illuminate a given area.

When deciding on lamps, consider the light output, color, energy efficiency, starting ability and projected life of the various lamp types: high pressure sodium, metal halide, fluorescent or incandescent. Keep in mind the advantages and disadvantages of each lamp type.

High Pressure Sodium

These lamps produce good light output in a warm, amber or golden color. They are long lasting and maintain their light output well, typically about 80% of their lumen output over the life of the lamp. The amber color may be inappropriate for applications where accurate color rendering is important.

Metal Halide

Metal halide (MH) lamps offer excellent light output, brilliant white light color, good energy efficiency and lamp life. The disadvantage of a metal halide lamp is the hot restrike time needed for the lamp to cool before it can reignite. Metal halide lamps also cost more initially than incandescent or fluorescent lamps.

Fluorescent

Fluorescent lamps offer high light output per watt, a range of color choices, good energy savings and long life. Many fluorescent lamps offer up to 10,000-hour average lamp life, meaning fewer lamp changes and lower maintenance costs. A 38-watt, 2D® fluorescent lamp produces the same lumen output as a 150-watt incandescent lamp while consuming 73 percent less energy. Keep in mind that fluorescent lamps don’t start as well as metal halide or high pressure sodium lamps at lower temperatures.

Incandescent

Incandescent lamps produce a natural warm light with a high color rendering index, are available at low initial cost and can operate in extreme temperatures. The disadvantages of incandescent lamps are low efficacy, the heat they generate and their relatively short life compared to other lamps.

Lamp Life

Lamp life is a main consideration due to the fact that security lighting is often on 24 hours a day. Consider lamp life expectancy factors and weigh the advantages and disadvantages of each lamp type with the demands of the application. High pressure sodium lamps are popular due to their extended life compared to metal halide lamps. However, you give up white light of the metal halide lamp for the longer life. The white light of metal halide lamps is desirable for many applications. Today’s metal halide lamps last longer than those made in the past, but still don’t outlast high pressure sodium lamps. Fluorescent lamps offer long lamp life while incandescent lamps don’t last as long as other types.

Housing Design

In addition to lamp type, consider fixture housing design, construction and material. Look for durable fixtures with die-cast housings or reinforced formed metal housings. Fixtures with electrical components mounted to a die-cast aluminum housing provide good transfer of heat generated by the ballast. In applications that are more susceptible to electrolysis and corrosion, avoid selecting housings made with dissimilar metals or high copper content alloy aluminum when possible because of their tendency to corrode. A powder coat housing paint finish and stainless steel screws help increase longevity.

Lens

Your choice of a glass or acrylic lens depends on the fixture design, manufacturer, application and cost. An acrylic lens is typically less expensive and lighter than glass. You can select borosilicate or tempered glass, acrylic or polycarbonate lenses. Molded borosilicate and flat tempered glass offers extreme high heat resistance, compared to plastic lenses. Acrylic lenses are more UV stable while polycarbonate lenses are more impact resistant but less UV stable than acrylic lenses. Acrylic lenses maintain their clarity more than polycarbonate lenses over time when exposed to UV light. In addition, polycarbonate lenses tend to yellow and lose their impact resistance over time with heat and UV exposure.

Also consider how fixture design effects ease of installation and maintenance. Picking a fixture that can be mounted in more than one direction can make it easier to fit a particular application. That can save you valuable time and money with multiple fixture installations. Consider if the fixture’s design makes it easy to mount and connect the wiring. Look for multiple knockouts for mounting over 4-in. square or octagonal and single-gang J-boxes. Housings with 1/2-inch conduit knockout entry points from the sides and rear can ease wiring. Check whether the fixture requires more than one person to install it safely.

Consider how fixture mounting location affects maintenance as well. Look for a fixture that is easy to open for relamping or cleaning. Check if the fixture’s gasket system is water- and insect-tight to keep out moisture, dirt and bugs. Getting a callback from a customer to replace a fixture damaged by weather or to clean insects out of the lens is inconvenient and cuts into your profitability.

Select a fixture that is less susceptible to vandalism. Choose versatile fixtures that mount where they are less likely to be damaged. Use protective features such as polycarbonate or tougher glass lenses that can withstand impact or install polycarbonate shields, wire guards or baffles to help prevent lens damage. Consider using tamper-proof screws and other hardware that deters fixture disassembly. Mount the fixture so that the motion control or photocell feature is as protected from vandalism as possible.

Finally, select fixtures designed to operate efficiently in the application’s operating conditions. Look for fixtures that hold up in extreme temperature change, freezing and thawing of moisture and the direct sunlight’s UV that can deteriorate housing and lens components. Consider how the mounting location affects the fixture’s long-term performance, maintenance and durability. When possible avoid mounting fixtures in or near areas of extreme temperature, moisture and dirt. For example, avoid mounting fixtures near building and traffic exhaust where they can accumulate moisture, dust, dirt and traffic particulate buildup.

Emergency Lighting

Completing an exterior security lighting project often includes providing exterior emergency lighting as well. When selecting emergency lighting fixtures, keep in mind the following information.

Emergency lighting is used when power failure or other emergencies occur. These fixtures must turn on instantly powered from a back-up power source such as an emergency generator or battery.

Emergency lighting fixtures are usually surface-mounted lamps that can be aimed. They can be wired to a remote emergency power source or include an integrated battery pack. The lamp types used in these fixtures are incandescent, tungsten, LED or fluorescent. The choice of lamp type can depend on energy source, cost and visibility requirements. Make sure the fixture is designed to operate within the temperature range of the application.

Choose a fixture with a maintenance-free battery that provides a minimum of 90 minutes of emergency power. Look for the longest expected battery life possible and select a fixture with a battery test switch and charge monitor indicator to ease maintenance. Surge protection on the battery charging unit helps maintain the battery for long life. Some fixtures also feature automatic brownout protection that switches the fixture to battery operation when the AC voltages drops below 80% of nominal. Look for fixtures that allow easy battery inspection, replacement, diagnostics and testing.

When selecting emergency lighting fixtures, make sure they meet National Fire Protection Association (NFPA), National Electrical Code (NEC), Building Officials and Code Administrators International (BOCA), local ordinances and regulations for fixture placement, brightness, power source, etc. For more information about security and emergency lighting consult the Illuminating Engineering Society of America Lighting Handbook.

Finally, select fixtures from a reputable manufacturer. Buy fixtures from a manufacturer with a reputation for making quality products and delivering your orders accurately and on time. Manufacturers that have earned ISO 9001 certifications can give you a level of confidence for products of consistent quality, performance and reliability. Look for good customer service and technical support before and after you purchase a manufacturer’s products. Some manufacturers offer to send fixtures for you to use for risk-free trial period to evaluate their product’s performance. Take advantage of those programs to test the fixture in an application. Check the length of warranty offered on the products you buy. Make sure the products are packaged well. Look for sturdy containers that open easily and break down with a minimum of pieces to cut down on job site waste. Select a manufacturer that offers flexibility in shipping to your location or directly to the job site. All of these factors help maintain your profitability by reducing wasted time waiting for product, returning incorrect or damaged product and disposing of a lot of packaging materials.

When completing a security and emergency lighting project, use your knowledge of fixture selection to provide the best security for your customer. Use the information above to make the selection process easier.

Paul Dybro is a Marketing Project Leader for Ruud Lighting, Inc. in Racine, WI.