Energy-consciousness and profit-consciousness go hand-in-hand. XtraMart, a chain of gas stations and convenience stores, has been making this connection since 1990 when it began installing controls on its lighting and air conditioning systems to reduce energy consumption.

Now the chain, headquartered in Thompson, Connecticut, has started putting controls on the refrigeration equipment in its 208 stores throughout New England, upstate New York and the Mid-Atlantic states.

“In making this effort, we’re following a basic business adage—saving money makes money,” said Tom Sansoucy, XtraMart’s Project Manager for Construction. “Every dollar we cut from overhead expense goes directly to our profit line.”

The XtraMart store in North Haven, Connecticut exemplifies how energy conservation measures can significantly cut energy consumption—to the tune of just over 26,000 kWh—by adding controls to in-store refrigeration units. “That store has a walk-in cooler with 14 glass doors and two free-standing freezers, one with two glass doors, the other with three.”

“This project began when XtraMart asked us to perform a free energy audit and submit a proposal,” Jim Staley, Chief Financial Officer and Chief Operating Officer of National Resource Management, a UI-approved vendor of energy management systems in Norwood, MA. NRM manufactures CoolTrol® Cooler Control Systems, which are specifically designed to optimize energy use in freezers and coolers.

The store’s walk-in cooler was equipped with electronic controls that automatically turn off the evaporator fans when the cooler’s compressors aren’t running. This saves energy since the fans do not, as is often the case, run continuously.

“This measure pays an indirect energy-savings dividend,” Staley said. “When the fans are running, their motors create heat which, in turn, cause the compressors to work harder because their job in the refrigeration cycle is to remove heat. Less heat means the compressors don’t have to work so much.”

Another energy-saving step addressed the problem of condensation forming on the 19 glass doors, obscuring customers’ view of displayed products, when cooler air in the coolers and freezers hits the warm air in the store. To prevent this, heaters are installed in the door and door frames to keep the glass condensation-free.

“The energy problem here is that these heaters stay on 24 hours a day,” Staley said. “The control system reduces the enormous amount of energy required for heating the doors by monitoring the store’s dew point and humidity. When the store is dry, like in winter or when the air conditioning is on in summer, the system automatically adjusts the amount of energy required by the doors based on the humidity levels within the store.”

“These are very effective measures,” said UI’ Small Business Energy Advantage program administrator Dennis O’Connor. “The evaporator fans use 35% to 45% less electricity, and further energy savings are realized from shortened door heater on-times—an 75% drop in electricity use for cooler doors and 45% for freezer doors.” According to O’Connor, the 26,000 kWh saved equate to almost $2,500 a year.

“We also expect lower equipment maintenance and repair costs,” Sansouci said. “Since the various cooler and freezer components won’t be running as long, there will be less normal wear and tear and, therefore, less necessary maintenance, as well as extended equipment life.”

Another important energy-saving measure XtraMart instituted was equipping the store with a Remote Site Manager to monitor and control the store’s HVAC, cooler/freezer controls and outdoor lighting via the Internet. The corporate Monitoring Center is in Thompson, but NRM

can also monitor equipment operation from Norwood.

“When we get an ‘energy alarm’ because a piece of equipment is down,” Staley said, “we’re responsible for alerting XtraMart of that fact so they can get their service group to fix it PDQ so there is no product loss.”

The price of that can be high. “If a refrigeration case goes on the blink, we could lose $3,000 to $6,000 worth of product in just one day,” Sansoucy said.

The Remote Site Manager serves three other energy-saving purposes. “First, it monitors energy use and, if consumption is running higher than preset limits, we receive alarms,” Staley said. “We can then either diagnose the problem online or send a technician to find the problem and fix it. This cycle of ‘continuous commissioning’ always ensures the equipment is running as energy efficiently as possible.”

The second advantage is that the site manager can avoid energy waste by setting up an on-line schedule to set the temperature to warmer or cooler by a few degrees during peak use hours.

“The third advantage is that we’ll get a signal when a store employee tries to alter the in-store controls on, for example, heat or air-conditioning,” Sansoucy said. “The site manager allows us to ‘lock out’ employees and prevent them from making changes.”

Does XtraMart think this effort merits the cost? In refrigeration controls alone, they’re balancing an upfront investment in the North Haven store of $5,600 for refrigeration control systems that will save them an estimated $2,500 in the first year of operation,” O’Connor said. “And don’t forget, total project costs are reduced by the $4,500 incentive UI paid under its small business program.”

In a word, it all sounds pretty convenient.

Contact:
Dennis O’Connor (203) 499-3715