We Deliver Solutions
Yes, we have some bananas!
Consider bananas. They're shipped to grocery distribution centers unripe, emerald green. Cool them too much, they turn black. Ripen them with poor air circulation, they turn blotchy lime, black and tan. They can cost the distributor a lot of "green."
Safeway modernized the fruit operation into a highly efficient series of flexible, accurately controlled refrigeration spaces called The Banana Rooms. Switching to computer control of ethylene gas and modulated glycol valves, along with adding forced air pressure fans, allows Safeway precision control over all environmental elements of The Banana Rooms. The improved control reduces ripening time and eliminates need for uncrating, then re-crating the bananas, resulting in significant savings of time, space, and labor costs.
The Logix system makes it all happen flawlessly, maintaining temperature to within one-half degree from 55° to 65°F and controlling humidity, cycling of gas, and air circulation velocity. The Logix system even monitors a door left ajar too long, shuts down the refrigeration, and alerts the operator.
The Banana Rooms, used for ripening other produce as well, have their own unique requirements. Yet Logix integrated them into the overall RCS design, giving Safeway pinpoint control within a comprehensive system. "Logix addressed each separate consideration throughout the warehouse," says Langlais. "That's what makes the system work."
With approximately five acres under its roof, the Safeway Warehouse in Bellevue, Washington, is among the largest cold storage and produce ripening buildings in the nation. Distribution center of more than eight million pounds of perishables daily to over 140 stores throughout the Northwest, it holds vast quantities of fresh, refrigerated, and frozen foods in 88 separate cooling zones. Each cooling zone has a different environment, requiring individual temperature, humidity, and operations.
Why did Safeway look to Logix to upgrade their operation's performance while reducing their existing energy consumption? "I thought hard about it," admits Brian Langlais, Maintenance Engineering Manager for the Safeway Warehouse, smiling about a decision well made. "Of the companies we looked at, Logix had by far the best system available. Their advantage is that they aren't just computer people, they're refrigeration people."
Energy bills may have soared in recent years, but advanced microprocessor technology has matched the pace. A state-of-the-art Refrigeration Control System (RCS) was just one of the projects Safeway was considering, but management saw it as crucial because it made good economic as well as environmental sense.
Following a thorough study of Safeway's existing operating system, Logix proposed a custom-designed microprocessor-controlled system with three operator control stations to provide better access and system integrity. Logix projected its RCS could save Safeway approximately 1.6 million kWH annually.
The Logix RCS was only part of a $750,000 performance upgrade and facilities expansion program, which included refrigerant conversion from freon to ammonia; addition of a screw compressor; addition of a new, larger condenser; installation of pressurized ripening rooms (see sidebar); and other energy consuming additions. Logix controlled the entire operation in a fine-tuned, integrated system that included some 1000 monitoring and control points.
Logix carefully coordinated installation of the control system and training with other upgrade phases of the project. The coordination paid off in no downtime for Safeway, a real benefit.
The new system provided other unexpected benefits. "One of our biggest surprises was that we discovered a number of mechanical problems we didn't know we had," says Ron Kitchner, Operating Engineer at Safeway Warehouse. "The Logix system lets us know at a glance exactly how our equipment is performing."
Perhaps the best surprise was how easily the staff made the transition to the new technology. "Logix really brought us out of the dark ages into the computer age of refrigeration control," says Kitchner, "but that can be pretty scary to guys who've never used computers before. The Logix system was very user friendly and intuitive."
"Another dividend was how much more control we now have over our entire system because of Logix data reports," Kitchner notes. Logix dynamic data-processing and reporting gives Safeway the analytical tools to improve operation strategy and system understanding. "And now, when there is an equipment failure or event, we can go back over the data and review what happened and when, perhaps preventing it from recurring instead of just scratching our heads and wondering what happened."
Logix proposed an integrated multi-tasking system of precision controls that would reduce evaporator fan operating time, provide advanced condenser control, sequence compressors to efficiently trim refrigeration capacity, achieve optimum suction pressure control, manage evaporator load, and improve evaporator hot gas defrost control.
"We also suggested some equipment changes we thought could boost Safeway's energy savings another 109,000 kWH/year," says Jim Conant, president of Logix, adding that Logix projections were based on a 50% compressor operating factor per year, manufacturer's performance data, and calculations for individual suggestions. "Actual operating hours could easily result in much higher energy savings," Conant explains. "And our projections don't even take into consideration the synergism that takes place when all the strategies are implemented, providing a combined improved performance/ reduced consumption effect."
Logix projections are conservative, especially in light of Safeway's expansion. "It's hard to figure exactly how much they've saved us because of all the other changes we made," says Safeway's Brian Langlais.. "But I can tell you that during our upgrade, we added a number of pieces of equipment that dramatically increased our energy consumption. During that time, Puget Power increased their rates about 16%. And we're spending about the same amount on energy now as we did five years ago. Draw your own conclusions."