SAN FRANCISCO — Danfoss highlighted the sustainability benefits of CO2 refrigeration systems in supermarket applications during a presentation at ATMOsphere America 2014 in San Francisco. Now in its third year, ATMOsphere America convened industry leaders to discuss the latest technologies, market trends, and regulatory issues in the field of natural refrigerants.

“With increased refrigerant regulations and growing interest in sustainability, CO2 is an ideal alternative for large charge systems like supermarkets to reduce global warming impact — by reducing leaks or eliminating the source,” said Peter Dee, sales and services director at Danfoss, during his presentation.

CO2 is a viable option to meeting a planned, orderly phasedown of hydrofluorocarbons (HFCs). It has a global warming potential (GWP) of one, compared to HFC refrigerants that have GWPs 1,300 to 4,000 times greater. Plus, based on a recent ASHRAE report, a transcritical CO2 system can reduce by 82 percent the total equivalent warming impact (TEWI) compared to a CO2 cascade system using R-134a.

“CO2 is an economically sustainable solution as well, offering lower lifecycle costs and improving energy savings by 10 to 20 percent through unique algorithms, such as gas cooler control and heat reclaim,” Dee continued. “Heat reclaim also makes it possible to achieve up to 95 percent reduction in refrigerant costs, allowing for supermarkets to obtain heating and cooling through one cost-effective system.”

To highlight the success of heat reclaim technology, Dee reviewed a project in which Danfoss helped to retrofit an 11,000-square-foot store. One CO2 booster system with heat reclaim now provides energy for cooling, hot water, and comfort heating — but with annual operating savings of $35,000 and a 7 percent TEWI reduction, attributable to the heat reclaim.

In the United States, Danfoss recently completed a project with Whole Foods Market in Brooklyn, New York — a demonstration project that the company said brought the first HFC-free supermarket to the United States in December 2013. During the conference, Dee discussed the role Danfoss played in the success of this new 56,000-square-foot store, which features a transcritical CO2 refrigeration system and a combined heat and power (CHP) system that provides baseline electrical heating and cooling load.

Danfoss provided a comprehensive control solution for Whole Foods’ Brooklyn store, including refrigeration rack, case, and system controls, and supported the design of the store’s HVAC system.

“CO2 is an enabler to achieving sustainability,” Dee concluded. “The technology is proven and exists today. And by achieving scale, return on investment also will improve.”

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Publication date: 7/14/2014

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