The commercial system, using a very low charge of ammonia (, 53 lbs, or .76 lb/TR) and 1,400 lbs of CO2, was installed at a Piggly Wiggly supermarket in Columbus, Ga., in 2015. The system was built by Heatcraft division Kysor Warren at its nearby factory in Columbus.
“It’s pretty much the same thing,” said Grady McAdams, Heatcraft’s director of cold storage sales, at the IIAR Natural Refrigeration Conferemce & Expo last month. “We’re now trying to grow that into the cold storage market.”
“ We’re now trying to grow that into the cold storage market.”Grady McAdams, Heatcraft
The industrial NH3/CO2 system covers capacities between 100 and 300 TR while the commercial version serves capacities up to 125 TR, said McAdams. The Piggly Wiggly store had an ammonia-cycle capacity of 70TR.
Like the commercial system, the industrial system uses a rooftop low-charge ammonia package on the high side and CO2 on the low side, inside the building.
The store was shown to cut its energy consumption by 33% on average – for a total of $74,640 in savings – over a 13-month period, compared to a similar store using HFC refrigeration.
Heatcraft, a traditional commercial refrigeration player, is also looking at targeting the industrial market with a large capacity CO2 transcritical rack.
“I think the interest has been almost equal on both” NH3/CO2 and transcritical CO2,” he noted. But, he added, “most people think it’s still a further leap to go to the larger transcritical systems [and say] I’ll see where I can get to with an ammonia cascade.”