Showcase for Sustainability
The IGA store in St.-Pascal de Kamouraska, Quebec, has the distinction of being the first supermarket in Canada to earn Leadership in Energy and Environmental Design (LEED) certification. A showcase of sustainable technologies, the store is expected to use 43% less energy compared to Canadian standards for similar buildings.
A good part of the savings is attributed to the heating system, which combines wall-mounted solar air heating, a form of heat recovery and fabric duct. It is completely sustainable and uses no fossil fuels, and provides 100% of the supermarket’s space-heating requirement (all three elements also were major contributors to LEED certification). When government and utility incentives were applied, the system had a zero payback time (or did not cost anything).
“Engineers consider two years or less a good payback on sustainable equipment,” said Simon Berube, senior director, store engineering, Sobeys Quebec, Quebec City, a subsidiary of Empire Co. Ltd. which operates more than 1,300 stores in Canada under such banners as IGA, Foodland and Sobeys. “But this store was paid back from day one.”
The space heating consists of a wall-mounted solar thermal system (by Enerconcept Technologies, Magog, Quebec), fabric ductwork (DuctSox Corp., Dubuque, Iowa) and heat recovery (SmartRed Compressor Systems Control, Vaudreuil, Quebec). A high-efficiency DX air-handling system (Carrier Corp., Syracuse, N.Y.) provides air conditioning, using the same fabric ductwork system.
Solar heating: The solar-heating system consists of an 1,800-sq.-ft. black metal “box” on the store’s southwest wall. The unit, mounted so that it protrudes six inches away from the building, heats outside air up to as much as 54 F above the outdoor ambient temperature. The system draws in outside air through the bottom and the heated air rises through a patented baffle system before it is delivered to the air-handling system.
The DuctSox fabric duct, which is 90% lighter than metal, is designed to provide maximized indoor air quality. It has linear vents that run the entire length of the duct. The vents disperse air more evenly than conventional metal duct/register systems, making the air-handler run times shorter.
“There aren’t drafts or cold/hot spots associated with conventional registers and generally the indoor air quality in the store is better with fabric ductwork,” Berube said. “In stores with metal duct/register systems, there are definitely drafts and customers typically feel chilled in the refrigerated-case aisles.”
Heat from the compressor racks is recovered and supplied to a plate heat exchanger to bring the solar-heated air up to temperature set points.
The refrigeration system features heat reclamation with a secondary glycol loop that reduces the store’s refrigerants requirement by more than 700 lbs. compared to a similarly sized conventional supermarket.
“Some day we hope to eliminate all refrigerants from our new stores,” Berube said.
In other green features, the store also has high-efficiency T5 fluorescent lighting, a parking-lot catch-basin system that separates automotive oils from rainwater and a complete building automation system for all mechanical equipment (by Carrier Micro Thermal Technologies). Also, water consumption has been reduced by 47%.
The St.-Pascal IGA is Sobeys IGA’s first LEED-certified building, but it won’t hold that distinction very long. The company is currently building a distribution center in Trois-Rivieres, Quebec, which will also be submitted for LEED certification, and a second supermarket, in Riviere-des-Prairies, Quebec, is in the process of obtaining certification.
“Today, all new Sobeys Quebec supermarkets are constructed according to the principles of sustainable building,” Berube said. “I believe it’s the social responsibility of all engineers to suggest the implementation of these technologies to their management because we’ve proven these products are available, functional and cost-effective right now.”