Major food retailers like Piggly Wiggly, Sobeys and Roundy’s are harnessing natural refrigerant technologies to deliver energy savings at stores across North America, heard participants in the ATMOsphere America conference in Chicago earlier this month.
Now in its 5th edition, this year's ATMOsphere America – held at the Westin Michigan Avenue on June 16-17 – was the biggest ever, attracting 340 participants from over 140 companies.
'Natural refrigerants are the end game'
As natural refrigerant solutions become more popular in the United States, participants in the event heard how there is increasing competition between different natural refrigerant-based technologies – whether R744, hydrocarbons or ammonia – for commercial refrigeration.
“Natural refrigerants are the end game,” said Keith Milligan of Piggly Wiggly, a self-service grocery chain with over 750 stores servicing communities in 18 states, highlighting the company’s commitment “to using natural refrigerants in every new store we build”.
At first, Piggly Wiggly considered all options on the table for improving efficiency and environmental performance across its store portfolio. But with the cost of synthetic alternatives to climate-damaging HFCs “skyrocketing” and the Environmental Protection Agency continuing to blacklist more high-GWP refrigerants under the SNAP programme, Piggly Wiggly soon became “fed up of changing our refrigerants to the latest and greatest synthetic refrigerant every few years” – and opted for natural refrigerants instead, Milligan explained.
Piggly Wiggly’s high-efficiency store blueprint uses natural refrigerants ammonia and CO2 in a cascade refrigeration system that harnesses technological innovations like an evaporative condenser, heat reclaim. Moreover, the firm sees its use of natural refrigerants as part of a wider sustainability strategy that encompasses LED store lighting, reduced lighting power density, and high-efficiency display cases.
Piggly Wiggly is reaping the benefits of installing ammonia-CO2 cascade systems in its stores. Heatcraft’s Masood Ali puts the cumulative savings to date at $33,170, equal to a 28.5% reduction in energy costs.
High energy savings, smaller environmental footprint
“Benefits include high energy savings, reduced environmental impact, the low cost of natural refrigerants, no regulatory concerns due to the low charge of the ammonia, and improved product shelf life,” Milligan said.
European retailers have seen great success with CO2 transcritical refrigeration, with over 5,500 stores having installed the technology to date. And CO2 transcritical is also making inroads into the North American food retail sector.
In Canada, Sobeys is investing in CO2 systems across its store portfolio. “Sobeys Quebec Inc. is a leader in CO2 transcritical refrigeration in North America,” said company representative Patrick Gareau.
Gareau demonstrated how installing CO2 transcritical systems had allowed Sobeys to reduce energy consumption by 8-10% compared to stores fitted with HFC-based technology.
The supermarket chain currently has 82 supermarkets using CO2 transcritical systems and is in the process of installing a further nine. Sobeys is also testing CO2 for air conditioning, he revealed.
James Hyland of Roundy’s, a leading grocer in the upper Midwest USA, explained how the Hillphoenix-Advansor CO2 transcritical booster system using CO2 as the only refrigerant had reduced their stores’ environmental footprint and efficiently covered both medium temperature and low temperature loads.
With these progressive companies driving change across the North American food retail sector, these are exciting times for CO2 refrigeration in the United States, Canada, and beyond.