While HFC refrigerants appear firmly entrenched in the HVACR industry landscape for the foreseeable future, it is interesting to see how so-called “natural” refrigerants such as ammonia, HCs, and CO2 could have an impact.

Now that the Environmental Protection Agency (EPA) has approved the use of three hydrocarbon (HC) refrigerants in some smaller appliance applications, advocates of HCs are continuing to promote use in larger equipment, with commercial ice machines as well as reach-in/walk-in freezers and coolers possibly next in line.

When talk first surfaced a number of years ago about using R-744 (CO2) in commercial refrigeration, there were two challenges — making the refrigerant work as a stand-alone in transcritical applications as well as in cascade systems and developing the components to make such approaches possible. Where does the refrigerant stand currently?

Using CO2 requires a different system design than the traditional HFC-based system. In fact, there are three standard design types that exist in the application of CO2 as a refrigerant in commercial food retail refrigeration systems. Each type can have variations to meet different requirements or to increase benefits.

The significance of a recent two-day conference was not only the extensive presentations regarding natural refrigerants such as CO2, HCs, and ammonia, but where the meeting was held — Washington, D.C.

One sector where CO2 is making the strongest inroads in the United States is in supermarkets as more stores and refrigeration manufacturers embrace its use. Where are two recent examples that make for good reading?

Two recent refrigerant developments focus on CO2 and HFOs. One relates to CO2 in refrigeration; the other is an announcement of an HFO in air conditioning.

My column in the Nov. 12 issue of The NEWS focused on HFCs, especially low GWP HFCs as retrofits for R-22 systems. This column will focus on what I used to call “beyond HFC” refrigerants, although these days, the term might be “other than HFC” refrigerants.

The use of CO2 as a refrigerant in transcritical refrigeration applications has received Underwriters Laboratory (UL) listing. Hillphoenix Inc. announced that its Advansor by Hillphoenix CO2 booster refrigeration system has received UL listing in both the United States and Canada.

The use of CO2 as a refrigerant in transcritical refrigeration applications has received Underwriters Laboratory listing. On Dec. 7, Hillphoenix Inc. announced that its Advansor by Hillphoenix CO2 Booster Refrigeration System has received UL listing in both the U.S. and Canada.