Case Histories: Retail Lighting
The Key to the Benefits of High-Benefit Lighting
Saving energy dollars is only a minor benefit to maintaining a lighting system properly.
by Cary S. Mendelsohn
In an effort to cut its lighting energy consumption, Sloan’s Supermakets in New York City decided to remove two lamps from each of its four-lamp fluorescent fixtures. The results were displeasing to the chain’s executive vice president. The stores looked dingy. He immediately directed staff to restore the four lamps to each fixture, but to use the most energy-efficient lamps available. The new lamps provided just as much light as the old ones (possibly more because they were clean), and the stores regained their visual sparkle. But more importantly, Sloan’s gross sales increased by as much as 15%. The explanation: Better lighting.
Consider the case of the Pillowtex Corporation showroom in the Dallas World Trade Center. The manager there spent a few thousand dollars to retain a well-known lighting system designer. The new system cost just $300 per year to operate and maintain, but the company credited the system with a sales increase worth over $900,000 per year. The pillows were displayed on glass shelves illuminated from underneath, creating a museum-like effect that absolutely wowed buyers who came to the showroom for the first time.
At Fairmont Fair Mall in Camillus, New York, a Syracuse suburb, new outdoor lighting generated only a modest lighting energy savings, because the new system–while far more efficient than the one it replaced– provided far more illumination. In fact, based on energy savings alone, the new system would have taken more than 100 years to pay for itself. Saving energy was not the focus of the shopping center’s manager, however. Sales were on the wane in part because of serious problems in the parking lot: break-ins, vandalism, muggings and worse. The company beefed up its security forces, but that did not change the appearance of the parking lot in the eyes of those who had the choice of shopping either there or at a better-illuminated mall nearby.
Fairmont Fair’s new lighting made a huge difference. Incidents of crime and vandalism almost disappeared because there was literally, no place for perpetrators to hide; no areas were shrouded in shadow or darkness. The lighting made the center far more visible from the road, promoting the center as a safe place to shop. As a consequence, sales increased by $2.5 million annually, increasing the owners’ sales-based rental income by almost $100,000 per year and elevating the resale value of the center itself. But that wasn’t all. Because better lighting permitted security officers to see more at any given instant, fewer officers and patrols were needed to achieve the same degree of vigilance. All told, the new installation paid for itself in less than 100 days.
Many managers focus on energy conservation as though the purpose of lighting is to use as little energy as possible. As John Bachner, communications director at National Lighting Bureau, explains it: “It would be like an Indy car designer running to A.J. Foyt and exclaiming, ‘I’ve just made our race car 40% more fuel-efficient.’ Imagine A.J.’s reaction were he to receive ‘I don’t know’ as a response to questions like, ‘How will your changes affect acceleration? Handling? Top speed?’
The purpose of a race car is to win races, not to consume as little fuel as possible. The purpose of retail lighting is to attract shoppers and help ensure their and the property’s safety in a parking lot, enhance the appearance of the store, help in merchandise inspection, stimulate sales, create product-specific ambiance, help speed product retrieval from storage, assist in review of receipts, reduce errors in logging in information, reduce the frequency and severity of accidents, reduce post-accident paperwork, lower exposure to liability and bad publicity, reduce insurance rates and more.”
Many existing lighting systems do not provide the quality of lighting needed to optimize task performance for a number of reasons. Often, the quality of lighting is not as good as it could be simply because the existing system does not comprise the newest technology available. Or the existing system was allowed to deteriorate because of inadequate maintenance. In some cases, a store’s original lighting system was designed to support the performance of tasks that are different from those being performed in the space today or to illuminate a work or shopping space that has been significantly reconfigured.
Although improving an existing system can achieve dramatic bottom-line results, the fact is that even the best-designed High-Benefit Lighting® system can quickly lose value if it is not maintained properly. If dust and dirt are allowed to accumulate on lamps and tubes, for example, the system will produce less light, and its ability to achieve certain effects–for example, adding sparkle to displays of crystal and jewelry–will be diminished. The amount of money saved by deferring such simple maintenance is small. The value of what could be lost is huge.
What does effective maintenance really involve? First of all, understand that lighting systems are just that: systems. More than just the electrical components are involved here. In most cases, when designing a system, the color of the walls and ceiling will be taken into consideration, as will the nature of those surfaces–i.e., matte or glossy. When dirt is allowed to accumulate on the walls or ceiling, their reflective characteristics change, and because they contribute to the effect of lighting, the entire systems is influenced. Outdoors, illuminating certain areas often will be affected by the growth of trees and shrubs. Where no shadow was cast five years ago, a significant shadow may exist today, providing a hiding place for someone up to no good.
Second, given the importance of high-benefit lighting, maintenance needs to be proactive. Lighting should be reviewed on a routine basis, to ensure it is functioning properly. Only checking for burned-out lamps does not comprise adequate maintenance. Inspecting the overall lighting system once every six months and after major storms should be implemented in a store’s maintenance schedule.
Third, lighting system maintenance needs to be organized based upon particulars of the system. A key issue in this respect is cleaning of lamps and luminaires (fixtures) and routine lamp replacement. Facility and maintenance managers need to recognize that it is not cost-effective to keep old but still operating lamps in place. It is not wasteful to discard lamps that still function, a notion that is so contradictory to some people that more explanation is needed.
With few exceptions, the lamps used for indoor and outdoor retail lighting purposes experience a phenomenon called lamp lumen depreciation, or LLD. As the lamps age, they produce steadily less light though the amount of energy they consume does not change. As the light diminishes, the system’s characteristics change. Depending on the specific types of lamps used, where they are located and a number of other factors, minor depreciation may have little effect. Over time, however, the depreciation starts to become a major issue as an area begins to look dingy; at that point, lamps need to be replaced. The expense associated with replacing operating lamps is actually smaller than replacing them once they have burned out.
Consider a retail lighting system comprising 200 fixtures, each housing four fluorescent lamps with a rated life of 20,000 hours. Assume further that the lighting is operated 5,000 hours each year, creating a situation where, for management purposes, we can assume that all lamps will have to be replaced sometime during the first four years of their operation. (In reality, of course, a number of the lamps will last much longer than 20,000 hours.)
Replacing lamps as they burn out (spot re-lamping) will probably take about 30 minutes to replace each, considering the time required for maintenance personnel to arrive on the scene, fetch a ladder and a lamp, move displays or other obstructions in order to set up the ladder, climb the ladder, remove the lamp, climb down the ladder with the old lamp and then go back up with the new one, install the new lamp, then go down the ladder, move displays, et al., to their original position, remove the ladder and return it to its storage location and discard the burned-out lamp. In fact, 30 minutes may actually be a conservative estimate.
With 800 lamps in place, employees go through this ritual 800 times in four years. Assuming that the labor rate involved is $15 per hour, the labor cost will amount to $1,500 per year (800 lamps/4 years x 0.5 hour/lamp x $15/hour). The cost of the actual lamps, given a hypothetical cost of $4 per lamp, will amount to $800 per year, for a total replacement cost of $2,300/year.
Now assume that the system is group re-lamped at 70% of the lamps’ rated life. (Please note that this percentage does not apply to all lamps.) With group re-lamping (and, typically, for luminaire cleaning too), all equipment, materials and personnel are assembled at the same time, usually after hours so employees and shoppers are not inconvenienced. As such, the time required to change one lamp falls to about 3 minutes (0.05 hour), and the overall labor cost becomes $214 per year (800 lamps/(4 x 0.7)years x 0.05hour/lamp x $15/hour).
While more lamps are replaced on average per year (286 vs. 200), costs will not usually increase proportionately, because, when group re-lamping is employed, it’s usually possible to obtain a bulk purchase discount. In this case, assuming a 15% discount can be obtained when 800 lamps are purchased at the same time, the cost would be $971 per year (800 lamps/(4 years x 0.7) x ($4 x 0.85)/lamp). As such, the total lamp and lamp replacement labor cost for group re-lamping would be $1,185 per year, which is $1,115 less (48%) than the cost of spot re-lamping.
As worthwhile as the overall maintenance cost savings may be, realize that the truly significant savings and benefit occur with respect to lighting system’s better ability to do the job it was installed to do, thereby increasing income and lowering expenses. Consider, too, that when group re-lamping is used:
Overall appearance is enhanced. Lamps all tend to age at the same rate, eliminating the effects that can occur when lamps appear to be different colors because some are four weeks old and others are four years old.
The lighting system will produce more light on an average basis. The average lamp will produce more light because it will be removed well before LLD lowers its output to unacceptable levels. You are more likely to obtain the amount of lighting the system originally was designed to produce, or, as discussed below, you might obtain more than you need, permitting significant savings.
Fewer lamps must be kept in inventory, because spot re-lamping will be the exception, not the rule. This frees up space for other purposes and reduces problems such as breakage and shrinkage. The potential of retrieving the wrong lamp from inventory is reduced. Managers can consider retaining a lighting management company by contract, freeing up in-house personnel for other tasks.
The group re-lamping schedule can easily be integrated with a group luminaire cleaning schedule. For example, luminaires are cleaned once a year; every third year, they are cleaned and re-lamped. Another important benefit of group re-lamping needs to be mentioned. In many instances, lighting system designers add compensatory lighting to their systems. Extra lighting is provided to compensate for the lighting loss they assume will occur as a consequence of second-rate maintenance.
A number of managers have found that when they plan lighting maintenance, including regular cleaning and group re-lamping, the system provides more light than is needed. The number of lamps and luminaires used can be reduced while still providing all the light required for high-benefit lighting. As a result, energy consumption and cost can be cut by 10-20% or more. Electrical demand can be reduced, as can the cost of labor.
What’s the situation at your retail establishment? The National Lighting Bureau recommends that you obtain the services of a qualified lighting professional to evaluate the existing system and its maintenance and operation. These professionals should submit a report that not only relates findings but also identifies options for making the system better so it more effectively achieves the purpose for which it was installed, while consuming less energy in the process. And for that extremely valuable goal to be achieved, effective lighting maintenance is essential.
Cary S. Mendelsohn, CLMC, is the founder and president of Chicago-based Imperial Lighting Maintenance and chairman of the National Lighting Bureau, a nonprofit educational agency.
This article originally appeared in Professional Retail Store Maintenance, September 1999. Reprinted with permission from France Publications, Inc., Atlanta, GA (770) 952-4300.