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A Canadian food distribution centre has combined the two most prevalent natural refrigerants, CO₂ and ammonia, in its warehouse expansion project, thereby fully eliminating F- gases from their site.

Looking for an environmentally conscious, efficient and affordable refrigeration and freezing system for its 18,500m2 facility Flannagan food services approached MYCOM Canada for a solution. Mycom, a susbisiary of Mayekawa, provided a custom made dual temperature ammonia/CO₂ brine packaged system able to efficiently store 200 tons of refrigeration at temperatures ranging from -15 to -28 ^oC.
 
The unit uses two large, insulated compressors isolated in an enclosed space. The compressors cool the CO₂, which is then pumped into those areas of the building that require refrigeration, thus reducing the ammonia charge the warehouse holds.

As a result, ”Flanagan enjoys the cost benefit derived from the efficiency of ammonia and feels comfortable knowing they are pumping CO₂ and not ammonia into the buildings”, Len Puhacz, manager of green technologies for Mycom Canada, stated.

Critical to the success of the system was a valve station that feeds CO₂ to the evaporators, flooded shell and the tube ammonia/CO₂ exchangers. The project used the ICF valve station from Danfoss, which provided ports for up to six function device modules that are configured specifically for a customer’s application. The valve station also had a design working pressure of 754 psig, making it suitable for use with high-pressure refrigerants like CO₂.

Environmental Concerns

“As we considered a system that would serve the new, larger facility, the low initial first cost of an F-gas system certainly appealed to us,” Rick Flanagan admits. However, conscious about ozone depletion, climate change and staff safety, the company opted for a combination of natural refrigerants.

Commenting on the return of investment for the system, Mr. Flannagan stated that “[Flannagan is] looking at a payback for this system of about 6.6 years, thanks to the energy savings it offers. And it is an environmentally friendly system that will reduce our carbon footprint and eliminate safety risk to our employees and the products we warehouse.”