Wal-Mart Canada opens store using CO₂ refrigeration

On 16 January, Wal-Mart announced the opening of the first environmental demonstration store in Canada, to serve as a blueprint for a series of stores the company plans to roll out within 2009. Each of the series stores is set to achieve energy efficiency improvements of at least 30 per cent compared to the company’s typical stores. The Burlington supercentre store is expected to even exceed this minimal energy savings, using an estimated 60 per cent less energy than the company’s typical store of equivalent size and reducing carbon emissions by about 141 tonnes.

CO₂ refrigeration contributes towards achieving 60% energy savings

The 129,000 square feet store incorporates a CO₂ refrigeration system supplied by U.S. manufacturer Hill PHOENIX. The low-temperature CO₂ secondary coolant system with a medium-temperature glycol secondary system uses water-cooled condensers on the high-side to achieve more than 80% charge reduction.

Talking to R744.com, David Hinde, Research and Development Manager of Hill PHOENIX, affirms that "[Hill PHOENIX is] excited to be part of this project that combines so many innovative features, including the refrigeration system which achieves new levels of charge reduction."
To provide further energy savings, the waste heat from the refrigeration system is captured and reused to heat the rest of the store. At night, both refrigerator and freezer cases can be covered to lock in the cool temperatures and are equipped with motion activated LED lights to save energy during the day.

Other technologies used to achieve the 60% reduction in energy use are primarily related to heating and cooling needs of the store. These include:

• Geothermal heating and cooling technology: First-of-its-kind demonstration of geothermal heating and cooling technology in a large-scale Canadian retail operation
   
• In-floor heating and cooling system: In-floor radiant heating and cooling system circulates water to transfer heat and cold instead of air vents, requiring less electricity
   
• Roof insulation: Increased insulation on the roof reduces heat and cooling loss
   
• Sunlight deflecting roof: White roof membrane deflects sunlight by an estimated 85 per cent to reduce heat gain in summer and demand on the electrical grid

The list of carbon saving features is finally completed by using means of enhancing the natural illumination of the store, sensors that assess the need for artificial illumination and 100% renewable sources to power the store.

About Wal-Mart Canada

Headquartered in Mississauga, Ontario, Wal-Mart Canada Corp. operates 316 retail outlets in Canada. Leading global retailer Wal-Mart is committed to reaching a day when every new store is 30 percent more energy-efficient than it was in 2005 and making existing stores 20 percent more efficient by 2012.