Read on to know more about the first 3 technology case studies selected for ATMOsphere America 2014's Commercial refrigeration session...

• Controlling Transcritical CO₂ Refrigeration for Sustainable System Design by Peter Dee, Danfoss

This presentation will examine the work done with Whole Foods Market at its new, 56,000-square-foot store in Brooklyn, NY – the first 100% HFC-free supermarket in the U.S., with transcritical CO₂ and CHP systems. To help meet the company’s sustainability objective, Danfoss provided a comprehensive controls solution, including refrigeration rack, case, and system controls, and supported the design of the store’s HVAC system to improve energy efficiency. Specifically, the presentation will discuss the refrigeration and energy management control solutions used in Brooklyn, and how these control strategies are scalable.

• First North American-Built CO₂ Copeland Compressor Supermarket Rack by Andre Patenaude, Emerson Climate Technologies

When Sobeys was building its latest IGA in Magog, Quebec, it chose to use CO₂ as the refrigerant to cool those specialized areas of the store that need strict temperature control. Sobeys chose Emerson Climate Technologies, which had significant experience designing CO₂ systems, to help meet the high-pressure challenges inherent in using CO₂. This presentation will show how the CO₂-based refrigeration system comprised of 11 transcritical semi-hermetic discus and four scroll compressors from Emerson Climate Technologies, including valves and drivers designed specifically for use with CO₂, provided Sobeys with reliability, efficiency and peace of mind.

• Adiabatic Gas Cooling Enables Expanded CO₂ System Geographical Applications by Tommy Gaubatz, Güntner US

The key to improving CO₂ refrigeration system COP in warmer climates is enabling the equipment to operate in a sub‐critical mode with as low condensing temperature as possible. This objective can be accomplished via adiabatic pre‐cooling of the ambient air for the gas cooler/condenser. Controlled testing of adiabatic performance has validated the system capabilities, and system ASHRAE weather bin‐based models predict the dramatic efficiency benefits for warmer climates. Based on the new performance levels, CO₂ systems will now be able to efficiently operate in all North American climates, effectively eliminating the final climatic barriers for more widespread adoption. Adiabatic systems can also achieve these results with significantly lower water use than traditional evaporative condensing systems.