R744.com: Tell us a little about the facility:
Jeffrey Gingras: Plaisirs Gastronomiques is an industrial plant that makes pies, sandwiches, pizza, pre-cooked food and many more products. They supply many supermarkets such as Sobeys, Provigo and Costco. This facility has four compressor rooms with a total of 12,000 lbs (5,443 kg) of R22 refrigerant. They felt it was necessary to find a solution to reduce the amount of R22 without risking any downtime of the plant, as this would impact their business. We worked with them to try to find ways to achieve what they where asking for and not stop any coolers during this very complex renovation.
R744.com: What was the motivation for the warehouse to call on LMP to switch up the system?
Gingras: We approached them with a solution to reduce the amount of R22 they have and replace it with a natural solution. Our goal was to use as much of the existing equipment possible. For the medium temperature side we opted for our ICE SLURRY solution, which allowed us to use the existing evaporators and add a pumping station for the ice slurry. The refrigerant charge would be restricted to the compressor rooms. Also by using this technology, Plaisirs Gastronomiques would not need to change all their compressors and their evaporators; they would just need to be adapted to the ice slurry solution. All the low temperature freezers are running with a CO2 cascade system that gets condensed into two screw compressors, which also act as sub-coolers for one of the ice slurry racks.
R744.com: The system is retrofitted to CO2 – what system components were/were not changed?
Gingras: All the freezers where retrofitted to a cascade CO2 technology. We were able to reuse the evaporators in all the freezers. All the other components had to be changed, as CO2 compressors and line sizing are not the same as those using R22.
R744.com: There are a few new all-CO2 additions to the facility as well – tell us about those.
Gingras: We really wanted try something new, so when Plaisirs Gastronomiques wanted a spiral freezer that runs at -40°C, we thought this would be a good place to try something that has not yet been done. We developed a very low temperature system that runs with a CO2 recirculation pump. The temperatures requested have been achieved, and the pizza is completely frozen after its cycle. It is a very innovative technology that runs solely with a natural solution. The results are amazing.
We also installed three blast coolers that work as DX CO2 transcritical systems. We are able to achieve our set points and are very happy with the results. Achieving the correct temperatures and delays that Plaisirs Gastronomiques needed was very important.
R744.com: The project is still a work-in-progress; when did you start, and when is it expected to be finished?
Gingras: The project was started in April 2013, and since then we have changed all the condensers to fluid coolers and are now ready to start our modification of the evaporators. We will be finished by April 2015.
R744.com: What are the expected energy/CO2 savings of the conversion?
Gingras: For the moment we have not looked into the energy savings they will obtain. Heat reclaim and hot water preheat will be installed before the end of the project. Monitoring the energy will be easily done thanks our new controller.
R744.com: Around how many CO2 warehouses do you think exist in North America? Do you think this is a growing industry? And if so, do you think it will catch up to the success of commercial refrigeration?
Gingras: We presently have the one. The demand for CO2 warehouses has dramatically risen in 2015; we have had many requests already this year. People are starting to look into ways to get rid of the R22 they currently have in their systems. Ammonia is not the solution for everyone when doing a warehousing retrofit, as some people feel more comfortable using CO2.
R744.com: What are your expectations for the industry overall for the coming year?
Gingras: I think public perception is changing for natural refrigerants. The upcoming year will be a time of evolution and many new systems will be built with new technologies.