Energy Savings: Sweating the Details
Part 2: Commissioning Systems, Evaluating Loads for Energy Savings
Commissioning Systems, Evaluating Loads for Energy Savings
By Naomi Millán, Associate Editor - September 2010 - Energy Efficiency
For some of the candidates, success has come from fine tuning strategies already in place. At the University of North Carolina at Chapel Hill, sustainability has long been part of the program, but tweaking the strategy at Morrison Residence Hall has netted still further energy savings, and the lead spot in the midpoint rankings with an EUI percentage loss of 19.2. That's not to say getting those savings has been smooth and easy.
Morrison is the second largest dorm on campus, and the only one with solar hot water (a 172-panel array), extensive submetering capabilities and an energy dashboard in the lobby. "It has historically been a testing ground for new technologies and initiatives," says Chris Martin, director of energy management.
But energy efficiency is never a set-it-and-forget-it proposition, especially not with newer technologies. Last year, the facilities team started fine-tuning the HVAC system to enhance the operation of the solar hot water system, which was at times providing too much hot water. With the advent of the contest, they went over the HVAC with an even finer-toothed comb, establishing standards for set points and air handler resets to operate on part load based on occupancy. Controls were enhanced. Martin estimates that the great majority of their success has come from tuning the HVAC.
The more efficient system has presented new challenges, such as data management. The hot water meters were in place before the system was adjusted; the more efficient system is now below their range, leaving the dashboard only partially operational. So the dashboard had to be retooled.
All of the tweaks were done with in-house expertise and fit under the umbrella of a wider initiative from the facilities department to conserve energy mainly through operational measures, like adjusting occupancy schedules. With an investment of $212,000 for improvements campus wide, the university saved $3.5 million in one year.
"It's a common preconceived notion that it takes capital, but what it really takes is the expertise and commitment of your own people," says Martin.
Hot on the heels of UNC with an EUI reduction of 18.3 percent is the Sears Glen Burnie team. Their basic strategy has been to do a reality check. "Verify what you think you know is actual," says Keith Klug, Sears Energy Project Manager for Sears Holdings Corporation. For example, weather stripping and delamping had already taken place, but they weren't as good as they could have been, he says. "You need to check everything once in a while. We became a little more critical."
A point of pride is their lighting retrofit from four lamp T8 fixtures to two lamp T8 fixtures. By using new interior components that reflect more light, in conjunction with high lumen output lamps and energy efficient ballasts, "the light levels increased in the store by 15 to 25 foot candles while decreasing the lighting kW consumption by approximately 40 percent," says Klug.
Push the Limits
The Sears team says they're "in it to win it" and so they are pulling out all the stops. One strategy they say they might not have considered had it not been for the contest is contracting a third-party to do a thermal scan of the store, looking for energy waste on everything from heat on motor bearings to improper weather sealing around the doors. The results have led the team to consider purchasing a few units and do their own thermal surveys across the portfolio, says Michael Brown, director of environmental sustainability and legal projects for Sears Holdings Corporation.
"We're not becoming infrared specialists, but it doesn't take you long to figure out that if there's a blue hue around a door during cooling season, the weather stripping needs improvement," says Brown. "We would never have thought of purchasing an infrared scanner for the portfolio had we not scanned Glen Burnie to try to find every single possible source of waste."
Outside of that, the top contenders say that the contest hasn't driven them to do too much beyond what they might have normally done anyway — they just stepped it up a little bit. That was the case at 1525 Wilson Boulevard in Arlington, Va., an office building managed by Glenborough, LLC. Having brought most of their West Coast properties into Energy Star scores in the 90s or higher, the company turned its attention eastward. A few months before the contest was announced, Glenborough had decided to tackle the capital improvements needed to reposition 1525 Wilson in its competitive market.
At the midpoint weigh in, 1525 Wilson was in third place, with an EUI reduction of 17.2 percent. From an Energy Star score of 45 over two years ago, the facility is now at a 95, says Carlos Santamaria, director of engineering with Glenborough. The first step was identifying the high use energy loads in the building.
In the all-electric building, the base building HVAC was found to be consuming 55 to 60 percent of the load. That, coupled with lots of hot/cold calls, prompted the facilities team to tackle the pneumatic air distribution system first. As funds became available, they installed DDC controls, repaired inoperable VAV boxes and installed new chillers with high efficiency compressors.
Santamaria says that there was a higher dollar commitment to 1525 Wilson due to its market than what the company can do in all of its properties, but every building doesn't need big capital to address its needs.
"If you can save 20 to 30 percent on 50 percent of the building load, that's where you focus," says Santamaria. "To make informed decisions, you really need to identify what your high-energy use loads are. That's the roadmap. Then you can allocate funds and make decisions."
And Glenborough's plan of attack doesn't start at the big capital expenditures. The company has a three-phase approach, starting with tracking energy use on Portfolio Manager and tightening operations practices, then moving onto mid-range capital improvements with a quick payback and then the bigger projects, like switching over to DDC, that are used when repositioning buildings. And then they start back at Phase 1.
The window for applicable energy data closed on Aug. 31 and the winner will be announced at the end of October. With contestants separated by only a percentage point, it's still anybody's contest to win.