Part 1: What Are You Doing to Conserve Energy?
As Mechanical Systems WEEK was in full swing a few doors down inside the Renaissance Hotel & Convention Center in Schaumburg, IL, 10 leading refrigeration professionals — five contractors and five supermarket executives — met with editors from Contracting Business.com and Supermarket News magazines, for in-depth discussions on the leading commercial refrigeration issues of the day. We’ll be sharing the proceedings here in the pages of CB, in a four-part series that will continue into 2013.
The Refrigeration Roundtable was made possible by the generous support of Danfoss, Emerson Climate Technologies, and Hill PHOENIX.
This month, we examine what our experts are doing to conserve energy, and working together as contractor/supermarket teams.
In an ideal world, supermarkets would be able to replace systems every 10 years or so. But since that’s not possible, the next best thing is to monitor and improve the efficiency of existing systems. Jon Scanlan, director, refrigeration and energy management for the 235-store Hy-Vee chain, said new refrigeration systems are one way to save energy, but optimization of existing systems is equally important.
“Hy-Vee’s refrigeration maintenance is very decentralized, and reliant on utility benchmarking. We identify outlying stores that use the most energy and try and go back and attack it from that angle,” Scanlan said.
“We use many types of compressors, including scroll compressors, screw compressors, and reciprocating compressors (by Copeland, Carlyle, and Bitzer). But, ensuring compressor reliability is a key to optimization; even more important than anything else.
“Moving beyond refrigeration systems, I think we all use LED lights, air conditioning EC fan motors, and we’re now putting doors on medium temp cases. I think a number of these things are becoming somewhat more standardized. A lot of what we’re doing includes recommissioning, and going back and verifying set points, and that sort of thing.”
Scanlan said Hy-Vee employs the services of Ecova, a commercial and industrial facility optimization company out of Spokane, WA. Ecova’s services enable corporate to run energy usage reports on a “per square foot” basis, and track those results against BTUH usage per store. It all leads to improved communication with store managers and contractors, to establish energy savings strategies.
“Improvements could be related to suction pressure adjustments, optimizing defrost times, upgrades to overhead lighting, or new case LED solutions,” Scanlan explained.
Paul Anderson, engineering group manager for refrigeration at Target, said true energy optimization begins with the understanding of the various energy factors that affect energy drain, as well as the human element, as it relates to management tactics.
“We’ve all experienced higher energy use events that were due to inefficient systems, components, lack of proper training, and good interaction with contractors or manufacturers prior to design/installation/equipment start-up. It starts with understanding the application you’re designing for,” he advised. “You have a particular store format, store size, and intended use of the equipment. Understanding the application and considering how the design will impact your total cost of ownership will go a long way in helping you achieve your goals.”
Anderson shared Target’s experience in evaluating compressors and refrigerants over the past few years
“There’s been a large focus in the industry related to what’s the best refrigerant, and how to get the best performance out of that refrigerant. We looked at some refrigerants that haven’t really been applied in supermarkets, such as R134A. Selecting a refrigerant with an optimized system or component will help you deliver the results you’re looking for,” he said.
“You have to help each other understand where there may be gaps in performance. Work together to close those gaps,” he said. “This can be accomplished through sharing performance metrics, training, following best practices or industry benchmarking. We have to bring it all together, to ensure that going forward, we achieve lowest total cost of ownership.”
Howard Hehrer, a senior engineer for Meijer, said Meijer also uses Ecova’s services to identify store that are higher energy users, to benchmark refrigerant load, and to develop a refrigeration recommissioning program.
One interesting improvement Hehrer shared was related to improving the performance of fresh meat cases in Meijer stores.
“We had an idea of where we wanted discharge air temperatures to be, based on years of experience. With the newer, more efficient cases, we were able to deliver a higher discharge temperature, case temperature, and still keep the meat at the proper temperature. By educating them, and doing some testing, we save energy on suction pressures by keeping the cases at a more reasonable temperature. That type of interaction is where we can score some big energy savings.”
Hehrer added that the more than 200 Meijer stores are “weeding out” older compressor systems, old parallel rack systems, and open drive systems, and moving to new, more efficient systems. Those practices are providing the biggest savings.
Ted Alwine, director of engineering for the 21-store Martin’s Supermarket chain, said Martin’s newest stores are working at optimizing ambient subcooling, which is a relatively inexpensive procedure to implement.
“By watching that process and maintaining proper head pressures, and allowing that to work for you we found some gains, at least as far as compressors not running as much in winter,” he said.
The size of “big box” stores makes efficiency especially challenging. Joe Gallego, manager, refrigeration and HVAC for BJ’s Wholesale Club, said the organization is starting to examine improvements in building envelopes.
“Typically, our older clubs were designed as a vanilla box, and nobody considered relative humidity or more importantly, dewpoint. We’ve really been addressing those issues over the past two years. I see many other chains now are starting to look at dehumidification systems, and controlling building envelopes. That makes a huge difference in the efficiency of the systems,” Gallego said.
Quest for New Ideas
Gallego is tenacious about looking for new ideas. He and his staff are always on the lookout for “low-hanging fruit” when performing remote store monitoring. He said he gives particular attention to tracking suction pressures.
“Also, we’ve gone through many of the clubs in the last few years, and have replaced every case to take advantage of the more efficient coils,” he said. “If we can get those suction pressures up there, and reduce compressor run time, energy usage goes down.”
Contractor Steve Tibbetts, owner of T&O refrigeration, Fayetteville, GA, works in close cooperation with major store chains. His latest improvements have been upgrades using Emerson’s E2 facility management system, CDS pressure regulating valves, and improving compressor staging.
“Most of our higher-energy use stores will have lighting issues, such as parking lot lighting that are out of control. We’ll see chains add 10 or 15 pieces of self-contained equipment, and don’t take energy usage into consideration, or the heat they’re putting back into the store,” Tibbetts said.
Contractor Mike Martin, president, Carlson & Stewart, Marshall, MN, works with many independent stores and those that are part of larger corporate chains. He said working directly with an independent store can be invaluable in decision making.
“With independents, we’re working with the actual owner that wants to put something into his store and have it energy efficient. We look at heat reclaim, water heat reclaim, and underfloor heat,” Martin said. “We’re making sure they have the latest in micro-processors. If they have older stores, to make racks more efficient, we install electronic stepper regulator (ESR) valves. We may replace an old compressor with an Emerson Copeland digital scroll compressor, to limit the cycling of compressors.
“Tim Uderman, contractor support manager for Emerson, has been working with us on those applications. We look at LED lights, ECM motors, splitting condensers, and liquid subcooling (mechanical or ambient subcooling). We look at optimizing defrost schedules, optimizing compressor cycling, floating suction, and floating discharge pressures. Anything we can do to help that customer,” Martin shared.
In-house store technicians and contractor technicians must communicate, to know the customers’ intentions with the systems. Bob Axelrod, president, Cooling Equipment Service, Chicago, IL, works with many food manufacturers and distribution centers. He said it’s very important to consider how the customer is going to be using the installed system.
“We try to look very closely at the temperature ranges they need, what process the food is going to follow, and what temperatures they need along the way; then, we tailor the systems to perform accordingly,” Axelrod shared.
“Virtually everything we do is either a custom-made rack or a custom-made condensing unit with oversized condensers, electronic controls, and electronic expansion valves. It’s all very much tailored to each individual job.” Axelrod added that this “value engineering” method saves customers huge amounts of energy over time. And, he finds ways to incorporate heat reclaim with digital controls.
“We wrote our own digital control program that looks at what’s going on in the system from a serviceman’s perspective. It tells him what he needs to know, so that if we get an alarm call, which we do over the Internet or by phone, they can solve a lot of problems right away.”
Jai Hoover, vice president, REMCO, Mechanicsburg, PA, emphasized the importance of educating technicians to follow a comprehensive preventive maintenance program, to ensure systems are set up correctly, and inspected regularly.
“Recommendations can be made to help reduce energy costs. We see a lot of chains who put stores in and kind of walk away from it. Then we get a call about high energy use.
“We focus on getting in there and checking transducers, making sure racks are set up correctly, going through the defrost cycle, getting onto the sales floor, cleaning the self-contained cases. All the things that drive energy.”
Of perhaps greatest benefit, Hoover said, is the way a contracting firm grows the expertise of its technicians.
“Technicians are a very difficult commodity to find. They can’t be beaten into the ground, and they have to be rewarded. You have to help reduce their hours, and if you can do a better job in your store, through improved preventive maintenance programs and keeping the calls down, it keeps them at home with their families.”
Our 2012 Refrigeration Roundtable Panel of Experts
Jon Scanlon, director, refrigeration & energy, Hy-Vee, West Des Moines, IA
Joe Galego, manager, refrigeration & HVAC BJ’s Wholesale Club, Westborough, MA
Howard Hehrer, senior engineer, Meijer, Walker, MI
Paul Anderson, engineering group manager, refrigeration, Target, Minneapolis, MN
Ted Alwine, director of engineering, Martin’s Supermarkets, South Bend, IN
Bob Axelrod, president, Cooling Equipment Service, Chicago, IL
Brent Beishuizen, service manager, Zone Mechanical, Chicago, IL
Jai Hoover, vice president, REMCO, Mechanicsburg, PA
Mike Martin, president, Carlson & Stewart, Marshall, MN
Ed Mattos, president, REMCO, Mechanicsburg, PA
Steve Tibbetts, president, T&O Refrigeration, Fayetteville, GA
SPONSOR REPRESENTATIVES :
Glenn Barrett, Jeff Staub, Danfoss
Al Maier, Tim Uderman, Kurt Knapke, Mike Saunders,
Sam Smith, Emerson Climate Technologies
Scott Martin, Derek Gosselin, Hill PHOENIX