Reducing Lighting Costs

Doug Carner Comments
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LIGHTING CAN ADD CURB APPEAL, SECURITY AND AFTER-HOURS CONVENIENCE TO ANY SELF-STORAGE SITE. In the last 10 years, there have been several amazing and dramatic advances in lighting. These new technologies produce natural light with far less energy. Let's start with some lighting basics.

If you look around your office, odds are you will see incandescent light bulbs. These inexpensive bulbs give a false impression of their true operating cost and are extremely ineffecient. First, much of the light they produce cannot be seen by the human eye. Second, because the light comes from a controlled fire, the bulb generates significant heat, which can translate into higher electric bills--especially in the summer when air conditioners struggle to keep rooms cool. While incandescent bulbs have the lowest upfront cost, they have the highest operating costs of any option.

The first major advance was florescent lighting, a technological marvel for its time. Florescent tubes were energized by a high-voltage source. The gaseous content of the light tube energized into plasma that radiated light. Early florescent lighting sliced electrical consumption to half that of incandescent. However, the bulbs were massive, and the light they produced was unnatural and harsh on the eyes. These early light fixtures also suffered from a significant light flickering each time they started and when bulbs began to die.

All light bulbs are rated by a color rendering index (CRI). A CRI rating of 100 is equal to natural sunlight. Early florescent bulbs, such as the vastly common F40CW, had a CRI rating of 62. By changing the light ballast in these older 4-foot fixtures, you can use 32-watt bulbs that have a CRI rating in the 80s or 90s. It is surprising how few sites make this change even though the bulbs are only $1 to $2 more.

More recently, fluorescents have changed shape to look like incandescent bulbs. Called compact florescents, they screw into common incandescent-bulb fixtures. The flicker effect has been eliminated, and the CRI index is generally in the 80 percent to 90 percent range. The major cost is for the ballast located at the base of the bulb, which will last four times longer than the bulb itself. If you choose a model with a replaceable bulb, your replacement savings will be significant. The bulbs should be replaced once a year, as their light output degrades over time.

Compact florescent bulbs are four times more energy efficient than their incandescent equivalents. If you use a prismatic fixture, the resulting light will be evenly dispersed. Because florescent bulbs provide low-watt comfortable light, they are the best choice for hallways, storage units and office spaces.

For outdoor lighting, you need a high output of light, measured in units called lumens. The most energy-efficient solution is the low-pressure sodium bulb. It is more efficient than florescent and much more efficient than incandescent bulbs. However, with their watermelon size and expensive fixtures, they have fallen far out of favor. Another problem is sodium bulbs emit extreme color saturation in red. This renders video-surveillance images nearly useless. High-pressure sodium bulbs provide a significantly smaller solution, but the red colors remain and the light efficiency drops dramatically.

Mercury-vapor bulbs are also more efficient than fluorescents, but they suffer from a strong turquoise hue that also hinders video surveillance. As such, sodium and mercury bulbs have become unpopular and quite expensive.

The magic bullet has come with the introduction of metal-halide bulbs. The current king is the "Pulse Start 320." This is a 320-watt bulb that generates an amazing 31,700 lumens of almost white light--more than six times that of a comparable incandescent bulb. This bulb should burn every night for five years and at a retail price of only $30.

The most common fixture for these bulbs uses an eyelet to provide a good cutoff and aim the light downward. When mounted at a 20-foot height, you will have bright, clean light spanning 40 feet in all directions. If you already have mercury-vapor fixtures at your facility, GE's I-line multivapor bulb can be dropped in as a metal-halide replacement.

Maximum Bulb Efficiencies
Bulb Type LPW CRI
Incandescent 16 100
Florescent 92 70+
Compact Florescent 60 90+
High-Pressure Sodium 130 60
Low-Pressure Sodium 166 85
Mercury Vapor 58 45
Metal Halide 99 70
LPW: Lumens Per Watt (higher is better)
CRI: Color Rendering Index (100 is natural light)

A self-storage site that switches from incandescent to a combination of compact florescent and metal-halide fixtures will see extreme savings in its lighting costs. If the light fixtures are attached to motion detectors, savings can climb to more than 90 percent. And if you can incorporate natural sunlight through windows and breezeways, you will gain a free, albeit unpredictable, light source.

Special thanks to Hans Joubert, president of Light Bulbs Unlimited (888.GET.BULB; www.lbuonline.com) for his extraordinary assistance with factual content.

Doug Carner is on the Western-region board of directors for the Self Storage Association. He is also the vice president of QuikStor Security & Software, a California-based company specializing in access control, management software, digital video surveillance and corporate products for the self-storage industry. For more information, call 800.321.1987; e-mail doug@quikstor.com; visit www.quikstor.com.

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