When some people think about heating potatoes and onions, they may be thinking about stew. But a fire at the Alsum Produce warehouse in Friesland, Wis., destroyed not only much of the stored stew ingredients, it also destroyed much of Alsum’s refrigeration equipment. Farsighted management at the company looked at this challenge as an opportunity for expansion and improvement.

Owners and management evaluated the situation and decided that this would be the opportune time to both expand operations and upgrade compressor controls for their refrigeration units. Actually, “control system” was almost a euphemism, according to Josh Vander Galien, vice president of operations and lead programmer for Advanced Energy Controls (AEC), a systems integrator specializing in refrigeration control, based in Randolf, Wis. “Their existing control system was just a thermostat on the wall,” says Vander Galien. The company had 14 refrigeration compressors at the old facility with individual thermostat controls.

“In fact, Alsum doubled its refrigeration operations within the facility,” says Vander Galien. “It was going to cost a lot of money to deploy separate control systems for this (now) more dispersed equipment. To save money, we designed a centralized control system with a rack architecture and distributed input/output (I/O) devices at the individual refrigeration units. We brought the compressors together in two racks. A rack is a bank of refrigeration compressors within one engine room. Within the rack, you can start and stop different compressors by size to get only the amount of compressor power that you want. For example, on this project, we can bring total horsepower (hp) down to where we can run 100 hp rather than the 250 they were running. We used an Opto 22 Snap Ultimate I/O system to control the evaporators and compressors.”

The system works by first tapping directly into Alsum’s main electric utility meter. These meters send a periodic pulse that provides the instantaneous electric demand in kilowatts (kW). The control system monitors this demand to determine the facility’s peak demand. Electric utilities typically impose an extra charge for exceeding a set peak demand limit. AEC’s system tracks the peak closely and sheds loads by switching off compressor units to assure that the peak is not exceeded. But rather than just shut off the first compressor it comes to, the system evaluates the entire facility and the refrigeration needs at every point. It can then make an intelligent decision on which units to temporarily shut off, producing a win-win situation. The peak demand is not exceeded, yet all refrigeration demands are met.

For example, at Alsum, the system knows when the bagging process is beginning and that it will consume electricity. The system then adjusts all the refrigeration units to assure compliance to the set allowable usage range. When the bagging process ceases operation, then the refrigeration units can be reset.

Proof of the energy savings possible lies in the numbers. Alsum doubled refrigeration units from 14 to 28, yet the electric bill stayed the same as before. In other words, a 50 percent reduction in energy usage was achieved.

Not satisfied with even that savings, Alsum and AEC extended the same concepts to facility lighting, heaters in its diesel-powered delivery trucks (necessary for starting the engines after overnights outside in Wisconsin winters), heat exchange in the potato storage area and battery chargers for forklift trucks.

Energy savings opportunities abound in facilities engineering, especially so in a venue where many people congregate—for instance in a hotel/casino complex. Located in the Renaissance Pointe area of Atlantic City’s Marina District, The Borgata Casino Hotel and Spa is the first new casino/hotel/shopping destination built in Atlantic City in more than a decade. The venue brings a Las Vegas-style concept to the Boardwalk.

The Borgata features more than 2,000 guest rooms, 135,000 square feet of gaming, 11 restaurants, a 35,000-square-foot spa, lounges, bars, shopping and entertainment facilities, and 70,000 square feet of conference space. Not surprisingly, employee and guest comfort is key to the success of this new facility. That comfort starts with the fundamentals: hot and cold water. To provide these essential services, The Borgata signed a 20-year contract with Marina Energy, a wholly owned subsidiary of South Jersey Industries. Under the agreement, Marina Energy provides the campus with a full range of heating and cooling services, as well as electricity and natural gas.

Marina Energy uses its brand new Marina Thermal Facility (MTF), a 26,000-square-foot plant, to provide the hot and chilled water needed to heat and cool The Borgata Casino Hotel. The $54 ...