Use of LED Lighting for Security Purposes

Having good outdoor lighting is a critical element in providing effective security at your facility. Having good lighting can discourage crime, make it easier to identify criminals, and make your employees and guests feel safer and more secure.

History of Outdoor Lighting

Since the late 1800's, a variety of different types of technology have been used to provide outdoor lighting. Initially, open arc lamps were used to provide outdoor lighting, but these were soon displaced by the incandescent lamp, which quickly became the standard for both indoor and outdoor lighting.

In the late 1940's, mercury vapor light fixtures were introduced, and offered the advantages of increased brightness, energy efficiency, and relatively long lamp life. One downside of mercury vapor lamps was the bluish-green color of the light that they produced, which many people found unpleasant. Despite this disadvantage, mercury vapor lights became a popular choice for outdoor lighting and street lighting in the 1950's and 1960's.

In about 1970, high-pressure sodium light fixtures came into use. High-pressure sodium lamps are very energy-efficient and quickly replaced the mercury vapor lamp as the preferred choice for outdoor and street lighting. Initially, people were turned off by the orange-yellow glow produced by the high-pressure sodium lamp, but they gradually became accustomed to this type of light. Today, high-pressure sodium lamps are the most popular type of lamp used in outdoor lighting applications.

Despite their popularity, high-pressure sodium lamps are not the best choice for all outdoor applications. In particular, the orange-yellow glow produced by the high-pressure sodium lamp makes it unsuitable when there is a need to accurately identify or display colors. Objects viewed under high-pressure sodium lamps may appear to be different than their actual color; for example an object that is blue may appear to be purple. This is undesirable in some applications, such as at auto dealerships, where it is desirable to display vehicles in their actual colors, or in security applications, where it may be necessary to accurately identify the colors of clothing and vehicles.

To meet the need for an outdoor light source that properly displays colors, metal halide lamps started to be used in some exterior lighting applications starting in the early 1980's. Metal halide lamps produce a true white light that allows colors to be properly displayed, overcoming this limitation of the high-pressure sodium lamp. Unfortunately, metal halide lamps cost more than high-pressure sodium lamps, are less energy efficient, and don't have as long of an operating life. Because of these reasons, metal halide lamps have not widely displaced high-pressure sodium lamps and are generally only used where their benefits outweigh the increased costs.

Other types of light sources have been used in outdoor lighting over the years, including compact fluorescent, low pressure sodium, and several others, but none of these have become widely-used alternatives to the high-pressure sodium lamp.

A New Concept in Outdoor Lighting

Recently a new type of lighting known as "LED lighting" has been introduced. "LED" stands for light-emitting-diode, a semiconductor-based light source that creates light through a process known as "electroluminescence". While most people think that LEDS are a new development, they have actually been around for more than fifty years. However, for most of these years, LEDs were only capable of producing a relatively small amount of light and their use was confined to things such as digital displays and indicator lights. Recent developments have created LEDS that are capable of producing much higher levels of light, allowing them to be used in general lighting applications in place of incandescent or other types of lamps.

The benefits of LED lighting are many and include:

• Energy savings: LED lights allow a 60% to 90% reduction in the amount of energy used.

• Long-life: LED lights can last up to 10 years or more.

• Better color rendition: LED lights are available that produce near white light, allowing colors to be displayed accurately.

• More directional: LED lights can be directed to the specific area where light is needed, avoiding "light pollution" in unwanted areas.

• Instant-on capability: LED lights can be turned on and off instantly, making them suitable for use with motion detectors and in other security applications.

• Ruggedness: LED lights are made of solid-state components and have no filament or glass envelope to break.

• Friendly to the Environment: LED lights contain no toxic materials.

• Controllable: LED lights can be dimmed and controlled for color.

• Flexibility: LED lights are available in a variety of form factors, including wall mounted fixtures, pole mounted fixtures, bollard fixtures and strip lighting fixtures. LED lamps that are direct replacements for incandescent and other types of lamps are also available.

Almost all of the major lighting manufacturers see LED lighting as the wave of the future and are rushing to bring LED products to the market. GE, Phillips, and Osram Sylvania all have LED products available on the market today and plan to introduce many more in coming years. It is reported that some manufacturers have abandoned research on other types of lighting technology because they can't see it competing with LED technology in the future.

Costs of LED Lighting

At the present time, the cost of LED lamps and fixtures can be two to three times the cost of metal halide and high pressure sodium lamps and fixtures. However, even though LED fixtures cost more upfront, the payback period (through energy and maintenance savings) is usually two to five years. Over a 10-year period, LEDs can save 50% or more compared to traditional lighting.

Many local power companies want to encourage the use of energy-saving technologies such as LED lighting and may offer one-time rebates and/or a reduced rate per kilowatt hour if LED lighting is installed. Some organizations may also be eligible to receive grants from government agencies to fully or partially fund an upgrade to LED lighting. This can alter the economics of the investment decision and may help justify the purchase of LED lighting.

Should You Upgrade Your Security Lighting to LED?

It is the opinion of Silva Consultants that LED lighting is the preferred choice for all outdoor security lighting and we recommend that all existing outdoor fixtures be upgraded to LED as soon as possible. When choosing new fixtures, we suggest that a color temperature of between 4,000 K and 5,000 K be used as it provides the high visibility and color accuracy necessary for security purposes. The fixtures should also be designed to reduce glare and to direct light only on the intended area to minimize light polution.

Also see related article: Evaluating Your Parking Lot Lighting