Targeting a broader range of commercial and industrial high-bay lighting applications, Digital Lumens has introduced new 18,000- and 26,000-lm, LED-based fixtures with integrated network controls. The new solid-state-lighting (SSL) products mark the first time the company has delivered IP-65-rated products for wet locations, and added a daylight-harvesting element to the company's Intelligent Lighting System.
Adaptive network controls have been at the heart of Digital Lumens' technology since the inception of the company, as its fixtures can deliver 90% energy savings by combining energy-efficient SSL with aggressive dimming schemes. The new products take the control capability to the next level by monitoring ambient light levels on a fixture-by-fixture basis ensuring no area is consuming excess power due to over lighting.
The existing 10,000- and 15,000-lm products have been deployed primarily in warehouses, especially in cold storage, where no significant ambient light is present. Senior product manager Joe Adiletta says that the higher-output of new fixtures will lead to usage in open docks, manufacturing areas, and even covered parking structures where daylight enters through windows, doors, other openings, and even skylights.
Fluorescent and HID replacements
The luminaires are meant as functional alternatives to 4- and 6-lamp fluorescent fixtures, and the company says the SSL alternative will yield significant savings over fluorescent lamps and even greater savings relative to HID lighting. Director of marketing Allison Parker said that the new fixtures can cut annual energy costs to $0.03/ft2 based on an electricity rate of $0.09/kWh. She said HID lighting can cost $0.46/ft2 annually.
“The higher lumen output, integrated daylight harvesting, and enhancements to the Intelligent Lighting System make Digital Lumens’ solutions more appealing to a broader range of our industrial customers, including those looking for lumen-for-lumen replacements of their 400W metal halide or 6- and 8-lamp fluorescent fixtures,” said Gary Hubbard, project manager for Leading Edge Design Group, a Digital Lumens reseller. “Facilities engineers are very interested in controllable high-bay LED lighting and we’re very excited to offer the expanded Digital Lumens portfolio to them.”
Like the prior Digital Lumens products, the new fixtures are controlled by the company's PC-based LightRules software that can communicate wirelessly with each fixture. Users can configure each fixture individually or in groups. And now the user can prescribe a light level that can be partially fulfilled by ambient light adding to the energy savings. LightRules can monitor and display the savings attributable to ambient light.
There are certainly other lighting systems on the market that use photocells to detect ambient lighting and feedback that information to a controller. Adiletta said, however, that Digital Lumens is the first to integrate sensors in every fixture offering more granular control of the light and the energy used.
Uniformity and transitions
The company also says the integrated sensor will improve lighting quality. Adiletta said, "You are going to get a much more even distribution of light across the space. And you will get a smoother transition from dim to light."
Parker said that the photocells that are added to competitive products add too much cost for deployment with each fixture. Digital Lumens minimized the cost by using image-sensor technology borrowed from cell phones and digital cameras and by relying on the microprocessor already integrated in its fixtures to process the sensor data.
The new fixtures look a bit different from Digital Lumens existing products, and that is primarily due to design elements that support the IP-65 requirements. The luminaires still include a trio of aim-able light bars, but those bars are comprised of multiple 6-LED modules that each feature optics that seal to rear housing and heat sink.
The new fixtures also feature a lower CCT of 5000K relative to the 6500K CCT of earlier products. The warmer CCT will certainly be favorable in some of the expanded scope of applications. Moreover, the change came with efficacy improvements to 85 lm/W (18,000 lm) and 81 lm/W (24,000 lm). Prior products had been in the mid-70-lm/W range and the efficacy improvement is primarily due to baseline improvement in LED technology.