Supermarkets operations result in significant greenhouse gas (GHG) emissions due to synthetic refrigerant leaks and energy consumption. Loblaw Companies opened an environmental flagship store in Ontario in 2008. This very large supermarket is the first in Canada to use carbon dioxide (CO2) as a heat transfer fluid for frozen food display cases.
Energy efficient supermarket
Several energy efficiency measures related to the design and operation of the refrigeration system, based on the CoolSolution® approach, were implemented in the Scarborough Superstore:
- Mechanical subcooling
- Floating head pressure
- Integration of the refrigeration system with the building heating, ventilation and air conditioning (HVAC) system
- Compressor superheat recovery
CO2 secondary loop
The CO2 secondary loop constitutes the most innovative aspect of the project. It is the first commercial installation of this kind in Canada and the largest one in North America. The CO2 in the liquid state is pumped to the frozen display cases and, when evaporating, provides an effective freezing of food.
CO2 is an excellent heat transfer fluid for secondary loops because it is not viscous, nor expensive, has better heat transfer properties when compared to brine, without being corrosive. It improves shelf life and food quality because of a more stable food temperature and reduces operation costs.
Data analysis results
Since the opening of the store, a set of operating data has been recorded and analyzed by CanmetENERGY. The analysis results confirmed the following:
- CO2 secondary loop refrigeration systems are favourable alternative to conventional, direct expansion (DX) systems found in most Canadian supermarkets
- The superstore achieves 23% reduction in energy consumption compared to a typical Canadian supermarket of equivalent surface area, and 59% reduction in GHG emissions, which translates into 2,700 t CO2eq.
For many years, Loblaw Companies have relied on innovative refrigeration technologies to reduce their GHG emissions. Within the framework of the TEAM (Technology Early Action Measures) Program Loblaw got involved with CanmetENERGY to introduce leading edge technologies and practices for refrigeration system design and operation, in particular CO2 as secondary refrigerant, in their new Superstore in Scarborough (ON).
- Date Modified: