What to Consider When Switching to LED
If you think an LED lighting retrofit is out of the question, think again.
Advancements in LED technology have greatly reduced luminaire costs, improved energy efficiency, enhanced lighting quality and reduced maintenance, making LED luminaires an ideal retrofit now more than ever before.
Across the industry, LED chip prices have decreased an average of 25% annually over the last five years, while efficacies (the “MPG” of lighting) have risen 12% percent annually in that time. Those rates of change are expected to slow significantly over the next several years – meaning many LED luminaires today offer exceptional value that will be hard to beat in the future.
Switching to an LED lighting solution has numerous benefits, and several key considerations will help achieve maximum results.
All LED parking garage luminaires are not created equal. Each product offers varying expected life and depreciation levels. For instance, some LED lighting solutions deliver 50,000 hours of life, or five years of continuous 24/7 operation, while maintaining 70% of the initial lumens. This is a dramatic improvement over a traditional 175W probe-start metal-halide lamp, which has a life of 10,000 hours (one year of continuous operation) and maintains only 55% of its initial lumens.
However, that pales in comparison with highly advanced LED luminaires, which have a 100,000-hour expected life (10 years of continuous operation) and maintains 87% of its initial lumens.
When selecting an LED luminaire, choose the option that has the longest life and the best performance. This will ensure that the facility reaps cost- and energy-efficiency benefits long after payback is achieved.
Cost- and time-effective retrofit projects require one-for-one replacements. Replacing existing products with twice as many (or more) LED units to achieve required light levels is counterproductive. This approach greatly increases the material and labor costs for installation, and doubling the number of luminaires could unintentionally increase energy usage rather than reduce it.
LED luminaires should be installed seamlessly in place of existing fixtures without relocating. This greatly increases the installation efficiency, reducing labor costs and significantly decreasing the amount of revenue lost when areas of the facility are closed for maintenance. Optics can make all the difference. Optical choices and optical quality are also crucial considerations. A luminaire with optical solutions for both single- and twin-row mounting, as well as for entry points, stairwells and other niches, will support a more energy-efficient retrofit.
Installing fixtures with only one type of optic throughout a parking structure can result in over-lighting some spaces (wasting energy dollars) and under-lighting others (posing safety issues), which amounts to poor uniformity overall.
The LED luminaire of choice should offer multiple optics to address all application types, and should install as a one-for-one replacement regardless of the previous fixture layout.
“For parking garage applications specifically, the most important optical factor when selecting a luminaire is glare; it should deliver the lowest level of glare possible,” said Craig Marquardt, Director of New Product Development, Outdoor / Optical Engineering at Acuity Brands. “Glare is measured with IES ‘BUG’ (backlight, uplight, glare) ratings on a scale from zero to five, with zero being the best and five the worst.
“Luminaires with poor glare ratings tend to lose control of light angles at high levels and become inefficient,” Marquardt said. “In general, a superior glare rating signals a very high-performing product overall – one that aims light directly on target and eliminates wasted light.
“A low glare rating not only impacts light quality, but also promotes a safer environment and greater energy efficiency. … The better the lighting uniformity and the lower the glare rating, the better the visibility,” he said.
Choose the correct wattage-and-lumen package. While many LED parking garage luminaires meet IES (Illuminating Engineering Society) levels for adequate illumination, this should be achieved with the lowest wattage possible. To accomplish this, select a wattage-and-lumen package that meets the parking facility’s specific needs to prevent over-lighting and wasted energy.
Lighting controls can deliver greater efficiencies. Programmed motion sensors can power down luminaires when an area is vacant and remain at reduced power until motion is detected. Ambient light sensors can reduce energy consumption by reducing luminaire output or turning the luminaire off as exterior light filters into the space during daylight hours.
When evaluating the cost of LED luminaires, consider not only the cost of the fixtures themselves, but also the savings in annual energy expenditures, the extended life of the luminaire and the reduced maintenance that is involved.
LED lighting is an excellent solution when retrofitting indoor parking facility lighting. The latest innovations in LED garage luminaires, paired with incentives and reduced maintenance, deliver a lower total cost of ownership.
Facilities can realize savings for years beyond payback. Additional planning – from selecting superior optics and long-life luminaires to enhancing the system with controls – will ensure a superior lighting upgrade.
Brad Dobbs is Value Stream Manager of Outdoor Parking Garage Luminaires for Lithonia Lighting, an Acuity Brands company. He can be reached at Bradley.Dobbs@AcuityBrands.com.
Article Abstract from July, 2012