LEDS - Shedding Light on the Future of Retail Lighting
Lighted merchandise will attract consumers and in turn yield greater sales than non-lighted merchandise. However, choosing the optimal light fixture for an application requires an understanding of options. Today, retailers have a whole new set of options stemming from the advancement of LED technology. Proper application of the new LED technology can increase profitability. However, improper application may lead to disappointment. This article will identify several key components and concepts to consider when selecting one LED light over another or replacing a halogen or fluorescent fixture with an LED fixture.
The three big common benefits of using LED lighting in merchandise displays are: lower heat, longer life, and lower power consumption. The value of these benefits to retailers are several fold. First, the lower heat generation reduces the risk of product degradation and injury to workers while retrieving product in cases. Additionally, the replacement of multiple halogen and PAR 30 and 38 fixtures can reduce the ambient operating temperature of a store and thereby reduce air conditioning costs. Second, LEDs in luminaires often have a life of 50,000 hours or five times the life of fluorescents and twenty-five times the life of halogens. Hence, there will be less bulb replacement and less maintenance cost. Moreover, the longer life of LEDs reduces the risk that a display will be dark during critical selling periods because of a bulb failure. Third, the substantial reduction in power consumption of LED luminaires over halogen bulbs and some inefficient fluorescent fixtures will lead to lower energy costs for the retailer. These lower energy costs will yield net profit increases.
Once the retailer recognizes the value of using LED technology in their store, the next step is to determine which LED luminaire is most suitable for the application. There are many more pieces to the LED lighting puzzle of which retailers are unaware. These missing pieces include LED life, electronic drivers, color, color rendering index, flexible fixture design, lensing, reliability, and third party certification. These missing pieces are crucial to reap the highest benefits of LED lighting. Effective purchasing of an LED light for a merchandise display or a retail display case requires an appreciation that all LED lighting fixtures are not equivalent and many benefits of high quality LED lights are not easily recognized.
LED life is often misunderstood. LED life span is measured as the time at which the illumination level is reduced to a specific level. Typically, LED chip manufacturers specify the life span of an LED as the time between first use and the time at which light output from the LED is 50 to 70% of the original light output. The LED is considered to have failed at the time the light output falls below this set level. If the LED circuit is not properly designed for the application, the life span of the fixture could be days rather than years. Remember, LEDs in luminaires often have a life of 50,000 hours or five times the life of fluorescents and twenty-five times the life of halogens.
The LED life, light output quality, and intensity of an LED fixture will be dictated largely by the electronic driver accompanying the LEDs, which is mounted on a printed circuit board. Even though it is difficult to see and hence evaluate the driver, it is important to understand the basics. The driver regulates the energy sent to the LED diode. There are generally two types of energy regulation: current or voltage regulation. DC-DC current regulation in a driver provides the best platform for long life and light output by feeding the LEDs with a constant current. The drawback of current regulation is that it tends to be more expensive and more fixture specific than voltage regulation. Voltage regulation crops the input voltage at a set level. The most common voltage regulation circuit utilizes a resistor. This type of regulation is relatively inexpensive, but may limit the life or impact the color emitted from the fixture over time.
The opportunity for LED fixtures to be used in merchandising has grown substantially with the development of white LEDs. LEDs are sorted by color using the Kelvin temperature scale. The higher the Kelvin temperature, the more blue or cool the color. Additionally, LEDs can be separated by their color rendering index (CRI). The higher the CRI, the more the color appears like indirect sunlight. The first white LEDs seen in the marketplace were usually very blue and had low CRI ratings. Now retailers can select various options for color and CRI depending on the application. For example, diamonds and jewelry are best accentuated by 4100K and a high CRI. In contrast, leather and dark tone products are usually better highlighted with 2900K LEDs and HICRI. In indirect applications that need maximum output, lower CRI fixtures often work best.
Fixture design can be just as important as LED chip selection. The fixture not only provides the design aesthetics, but also dictates the function. For example, linear lights with adjustable end caps are well suited for directing light in long cases. Additionally, fixtures that are incorporated into a DC system can make installation and retrofits easier, cheaper, and quicker; all of which provides a faster return on investment.
As light output from LED chips has increased, designers are beginning to recognize that a LED fixture needs to balance output and aesthetics. The directed nature of LED lighting ensures that up to 95% of illumination reaches the targeted area rather than being lost in the back of the fixture. The cones of light emitted from LED fixtures are born from many different factors; the angles on the LEDs, the reflectors used in the light, the arrangement of the LEDs in the fixture, and/or the fixture’s lens. Narrow cones are good for focusing light on a spot. Wider cones are better for illuminating an area. Fixtures with LEDs that create a flow will fill an area with light more effectively than fixtures with bright spots. Additionally, bright spots may be perceived as harsh or cause eye strain. This recognition that an overhead or courtesy light is not a flashlight has led to new flooding LED angles and fixture designs.
Identifying a quality LED fixture is difficult because many LED products are flooding the market with bold claims and little support. This situation has created a “buyer beware” environment. It is prudent to consider a manufacturer’s experience and history in lighting and LEDs when assessing LED fixtures. Additionally, be sure to look for listing and/or testing information because this indicates that an independent third party has tested and supports the maker’s claims. Third party certification (FCC, ROHS, CE, CSA, UL 1500 and ENERGY STAR®) of the fixture can provide guidance on the quality of the fixture.
To maximize the return on investment when selecting LED fixtures, retailers must be educated to choose the right LED fixture for the application to maximize sales and return on their investment using new LED lighting technology on merchandise. Assessment of the investment must include hard cost, such as cost of the fixture, maintenance, and operational costs of the old and new fixtures. Similarly, but hard to measure, are gains associated with better illumination. Some industry experts suggest LED fixtures can increase sales 3-5%. If the purchasing analysis is limited to LED versus incandescent and any LED light is accepted as a fluorescent or halogen replacement, a purchaser may be disappointed. The retailer may have to replace defective fixtures for premature failures, or have the wrong color light on its merchandise. Consultation with professionals with experience in LED lighting can direct you on how to shed the best light on your merchandise.