Below is my contribution to the February issue of tED Magazine. Reprinted with permission.
Skeletal frameworks installed in some facilities form interior subspaces called bays, often characterized as high-bay (>20 ft. off the floor) or low-bay (<20 ft.). Such high-ceiling applications are common in industrial, warehouse, big-box retail, convention center, and gymnasiums. General lighting installed in high-bay applications typically involves high-output luminaires emitting 15,000 up to 100,000 lumens per luminaire. These luminaires often operate at least 12 hours per day, making them good candidates for energy-saving options for both retrofit and new construction.
Traditionally, high-intensity discharge (HID) lamps dominated this large market, which saw significant displacement in retrofits based on high-output linear fluorescent. In recent years, manufacturers rolled out LED high-bay luminaires that promise high energy savings compared to both options, along with other significant advantages such as superior life and controllability.
The U.S. Department of Energy (DoE) estimated LED penetration at less than 10 percent of the overall installed industrial lighting base in 2016 (up from 6 percent in 2015), indicating a sizable estimated retrofit opportunity of 82.4 million high- and low-bay luminaires. In new construction, the big drivers are energy codes and energy-saving opportunities, while in retrofit, the big drivers are utility rebates supporting LED technology, particularly premium efficiency luminaires and controls, along with regulations that are restricting available of less-efficient lamps and ballasts.
“In terms of performance, LED high-bays are leading the way for all indoor fixtures,” said Eric Meadows, Global Product Manager Industrial LED, Current by GE. “Several years ago, I don’t think you’d really be able to claim that LED fixtures could compete with T5 fluorescent lamps, and really the industry was primarily targeting 250/400W HID products for LED replacement. Today, we are absolutely going after the most efficient fluorescent technologies in retrofit as well as new construction and having incredible success due to the price-performance combination available today.”
Meadows added that typical LED luminaires are generating about 50 percent energy cost savings compared to HID and 30-40 percent against fluorescent. Premium-performance options offered by the top-tier manufacturers are going even further, saving 70-80 percent over HID and 55 percent over fluorescent. The best-performing products, he pointed out, are edging close to LED technology’s theoretical maximum efficiency in a practical application. As of September 2017, the most efficacious product listed in DoE’s Lighting Facts database was a 108W high-bay luminaire emitting more than 22,000 lumens, resulting in an efficacy of 210 lumens/W.
“There is a vast range of LED high-bays available on the market today that feature a variety of options for light output, size, optics, wattages, CRI [color rendering index], and CCT [correlated color temperature],” said Joe Engle, Product Manager, New Product Innovation, Hubbell Lighting. “Controls integration and compatibility continues to progress quickly, and we’re now using drivers with 0-10V control leads to ensure they are control-enabled. It’s likely there is an efficient, reliable, and affordable LED high-bay for every application.”
Image courtesy of Hubbell.
Trends
Engle and Meadows pointed to several major trends in LED high-bay luminaires:
Increased efficacy: Rising LED source and optical performance is being leveraged by manufacturers to increase light output, reduce wattage, or both, resulting in higher efficacy (lumens/W). It is also contributing to smaller luminaires, which is contributing to a steady average decline in cost, as well as lower operating temperatures and longer life.
LED high-bay luminaire are now available in standard and premium efficiency options. The most-efficient luminaire are recognized as Premium in the DesignLights Consortium’s (DLC) Qualified Products List, qualifying them for potentially higher utility rebates.
More options: LED high-bay luminaires are available with a wide range of light distributions, CRI, and CCTs. Meadows said the most popular CRI continues to be 70, as it is not only suitable for a majority of industrial and warehouse applications, but also the most efficient LED chip package.
Uplight: LED high-bay luminaires are available in inverted mounting for indirect lighting.
Optical control: TIR optics enable greater optical control, which reduces glare while potential reducing the number of luminaires required through control of the beam spread. Engle said there is a trend toward lensing for luminaires installed at lower mounting heights in logistics and warehouse buildings to reduce direct glare.
Lighting controls: This is a major trend, with LED offering the ability to both dim and turn OFF loads when they are not needed either through scheduling or integrated occupancy and daylight sensing. While standalone sensors and hardwired circuit-level controls remain most common, wireless connectivity and digital communication are nascent but becoming more popular, particularly for flexibility in both retrofits and new construction. DoE estimated penetration of connected lighting systems at about 0.5 percent of the total installed industrial lighting base in 2016, indicating enormous potential.
“In new construction, it means that a control scheme can be laid out and then reorganized again and again with very little costs associated with changing the layout,” said Meadows. “It’s also more common that they have the option to connect to a building management system and even collect and aggregate data that could be utilized to unlock value at a facility.”
What to look for
“Electrical distributors want performance and reliability in a fixture that is affordable and reliable,” Engle said. “The preferred method to confidently select a product is to purchase a DLC-listed LED high-bay from a manufacturer that has proven it will stand by its product.”
Meadows agreed but noted that DLC qualification does not provide assurances about product quality. “This is why we see distributors consistently pick a brand name manufacturer with whom they have a high degree of confidence. There are plenty of lighting companies that are offering longer warranties as standard. Still, the best warranty is one that you don’t have to use because the manufacturer thoroughly tests and controls product quality and has a vested interest in producing quality products.”
Final word
“Sensor-enabled high-bay LED light fixtures are the easiest way to reduce energy and transform your customers’ facilities for the future, and now are at a price and performance that make it a true no-brainer to switch to LED,” Meadows added. “If you’re still selling fluorescent lamps or fixtures that don’t communicate digitally, someone will be there to earn your customers’ business with a fantastic intelligent LED solution.”
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