Danfoss highlighted the sustainability benefits of CO2 refrigeration systems in supermarket applications during a presentation at ATMOsphere America 2014, June 18-19, 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. This also was the third year Danfoss was a sponsor of the conference.
“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.
According to Danfoss, as a proven solution in other regions of the world, like Europe, 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% of the total equivalent warming impact (TEWI) compared to a CO2 cascade system using R134A.
“CO2 is an economically sustainable solution as well, offering lower lifecycle costs and improving energy savings by 10 to 20% through unique algorithms, such as gas cooler control and heat reclaim,” Dee continued. “Heat reclaim also makes it possible to achieve up to 95% 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-sq-ft 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% TEWI reduction, attributable to the heat reclaim.
In the United States, Danfoss recently completed a project with Whole Foods Market in Brooklyn, NY. The demonstration project 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-sq-ft store, which features a transcritical CO2 refrigeration system, and a combined heat and power 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.
“We deliver a comprehensive CO2 product portfolio that combines mechanical and electronic controls — offering a systems approach with flexible, customized options configured to meet end user needs and taking into consideration the requirements for safety and ease of use,” Dee explained.
Danfoss officials said the Whole Foods Brooklyn project demonstrated the need for — and success of — strong industry collaboration among the controls provider, OEM, contractor, and end user in designing and installing CO2 refrigeration systems.
“CO2 is an enabler to achieving sustainability,” he concluded. “The technology is proven and exists today. And by achieving scale, return on investment also will improve.”