A lot of talk these days about natural refrigerants focuses on CO2, propane, isobutene, and the like. Stateside, they may be new kids on the block in terms of HVACR applications. But one natural refrigerant that has been around seemingly forever is ammonia. So it - like those “newcomers” - is drawing a lot of attention.

At the Euroshop 2011 Expo in Dusseldorf, Germany, in March, Carrier Corp. introduced what it called “the latest innovations in CO2 and hydrocarbon refrigerant solutions, turnkey and heat recovery systems, and after-sales support and services for the food retail business.”

While CO2 is being successfully used in subcritical applications in the United States, it is more of a challenge in transcritical situations because of demanding compressor technology and high pressures. The UK office of Sanyo Air Conditioners recently issued two case histories showing the refrigerant being used for heat pumps in commercial applications.

During a climate seminar event toward the end of 2010, members of the Consumer Goods Forum, made up of European sector manufacturers and retailers, announced intentions to ban their use of refrigerant gases that they said had high global warming - including HFCs - by 2015 and to replace them with natural refrigerants.

While refrigeration in supermarkets information ran throughout sessions at the Food Marketing Institute Energy & Store Development Conference, it also found itself as a stand-alone topic during several concurrent breakout sessions and as a front and center focus of a general session.