2013-04-16

LED Retrofit Saves Manufacturer an Easy 40%

Mack Technologies, a specialty manufacturer in Massachusetts, is a poster child for the kind of savings LED lighting can enable; and they're just getting started.

Mack makes electronics and circuit boards for the defense, telecom, and industrial sectors in a 130,000-square-foot (12,077 sq. m) manufacturing facility in Westford, Mass. Between October and December of last year, Mack replaced 2,600 T-8 fluorescents with LEDs. It was the largest LED manufacturing installation in New England to date, according to Bluestone Energy, the firm brought in to run the project for Mack.

The new lights are dimmable, independently controllable, and capable of being assembled rapidly into arbitrary control groupings. They provide more light on the floor than the tubes they replaced, while saving the company 40 percent on their energy bill, or $50,000 per year -- and that's just the early results. Greater savings will come as Mack gains experience with the lighting control software.

The project cost Mack about $200,000 after federal and state energy tax credits and incentives from the energy supplier were accounted for. These savings amounted to about $125,000 and enabled Mack to take on the lighting project earlier than it might otherwise have been able to justify.

The incentives from the energy supplier, National Grid, weren't really free money: Heavy users of energy pay into a fund to underwrite such incentives, so in a way Mack was drawing on money the company had already spent on its monthly energy bill.

Control system
The project manager, Bluestone, chose a control system from Daintree Networks for the Mack project. Bluestone is a VAR for Daintree -- the two companies met up at last year's Lightfair, as Bluestone's Sean Fuller, VP of business development and marketing, told me in an interview.

I spoke with Daintree's VP of channel development and marketing, George Stringer, about the Mack project and about Daintree's ControlScope Manager software. This software controls lights through a ZigBee (802.15.4) mesh network implemented by adaptors installed alongside the driver in each lighting fixture. At Mack, the fixtures are typically 8 to 10 feet apart; Daintree's mesh works at separations up to 100 feet. A network can span up to ten thousand nodes across a hundred buildings.

Image: Daintree Networks

The adaptors all monitor power usage, and ControlScope Manager presents a dashboard and numerous reports and analyses of patterns of power usage, in real time and historically.

CSM makes it relatively simple (as the video linked above shows) to define and refine zones of lighting that can be controlled as a group on a schedule, on demand, or via sensors based on occupancy.

Foot-candles on the ground
The new LEDs at Mack put more light on the ground than the fluorescent T-8s they replaced -- two to three times as much, according to Daintree's Stringer. Mack Technologies CEO John Kovach explained to me in an interview the process Mack went through to specify the desired lighting levels. Both the IES Recommended Practices and the standards for circuit-board manufacturing promulgated by IPC call for an illumination level of 90 foot-candles. Bluestone performed measurements on various fixtures from their chosen supplier, Lithonia, and settled on 24K-lumen model, the I-Beam LED (PDF), which operates at an efficacy of 91 lm/W.

Greater savings to come
Daintree's Stringer told me that the company designs its installations conservatively, so as to under-promise and over-deliver. The initial savings that users of its control system see via the CSM dashboard can easily be improved as the users gain experience with actual usage patterns.

Daintree's system can actually control more than just lights. Stringer referred to this capability as "multi-measure": handling lighting plus plug loads plus heating and air conditioning. Mack's CEO, Kovach, said the company is definitely interested in exploring these further avenues to energy- and cost-savings down the road.

Kovach told me that after the new system was up and running, the facilities people performed an experiment in cooperation with Bluestone. They decreased the lighting in one area from its nominal 90-foot-candle level in 1-percent increments. Not until the level reached 50 percent of spec did they perceive the lighting to be noticeably dimmer. So while Mack is already saving significant money on its lighting bill, it evidently has plenty of headroom to wrest more savings from the system.

Building momentum for LED conversions
Bluestone's Sean Fuller told me that the company, which operates nationally, is seeing rapidly increasing demand for LED conversion projects of this sort. "We are doing way more high-bay and exterior than anything else," Fuller said. "Not so much office. The cost savings are not as clear there."

As if to underscore this point, Mack replaced old T-8 fixtures in their dropped-ceiling office space with -- wait for it -- more efficient fluorescents. The field is moving fast, and when the project was being specced LED replacements for warm-white fluorescents weren't as plentiful or as cost-effective.

Bluestone is agnostic with regard to lighting sources, Fuller said. It uses whatever works best and most economically for the requirement at hand. Fuller noted that Sylvania had recently introduced a fluorescent fixture with a claimed lifetime of 84,000 hours, subject to certain restrictions on how often the power is cycled. So contrary to the prognostications from Philips (this site's sponsor) that LEDs may eclipse fluorescents in 10 years' time (Acuity says three years), the older technology may not be rolling over and dying quite so fast as all that.

— Keith Dawson , Editor-in-Chief, All LED Lighting