Refrigerants

Today worldwide concerns about Earth’s fragile biosphere loom large, and refrigerants are once again a target in the environmental debate.

Although ozone-depleting refrigerants were banned years ago by the United Nations Montreal Protocol, the current discussion has shifted to greenhouse gases – chemicals with high global-warming potential (GWP), including contemporary refrigerants such as hydrofluorocarbons (HFCs).

Europe’s recent F-Gas regulation phases out all automotive air conditioning system refrigerants with GWP ratings greater than 150 by 2017. Bans on certain HFCs are also being enacted in some European countries and are proposed in California in the United States.

These developments have raised concerns within the shipping industry about the long-term prospects of their refrigeration technology investments.

 “Carrier is closely watching these trends and looking ahead to the future,” said David Smith, senior product manager. “In the meantime, R-134a, which is used throughout the Carrier container product line, remains the most environmentally sound refrigerant presently used in container applications.”

A high-performing, cost-effective, non-flammable and non-toxic refrigerant, R 134a has the lowest GWP of any non-ozone depleting refrigerant used today. At the other end of the spectrum, R-404A, an HFC blend used in some competitive container applications, has the highest GWP – 2.5 times greater than R-134a. With a GWP rating of 3260, R-404A is capable of trapping 3,260 times as much heat as carbon dioxide on a pound-for-pound basis.

One expects that with a well-made system, the chance of refrigerant ever escaping into the atmosphere is slight or not at all; however, R-404A has a relative leak rate 3.6 times that of R-134a, and once released into the atmosphere, R-404A has a lifespan of 48 years, versus only 15 for R-134a.

“Some manufacturers claim that R-404A is superior because it offers greater deep frozen capacities than R-134a,” said Smith. “The fact is that less than 5 percent of refrigerated cargo is in the deep frozen range, and most of that is kept at -24oC to -25oC ( 11.2oF to -13oF), which R-134a units have handily accommodated for many years.

“With the new PrimeLINE™ unit, Carrier’s world-class engineering has resulted in even higher deep frozen capacity than any R-134a unit, and it provides about 10 percent more pulldown capacity than the nearest rival.”

To sum, R-134a delivers environmentally sound performance for container refrigeration, and its use in container fleets is currently not affected by any bans. The F-Gas regulation in Europe is specific to the use of R-134a in automotive applications only.

“Further, if bans are at some point imposed on HFC refrigerants used in container units, we certainly would expect them to affect all HFCs, not just R-404A or R-134a,” said Smith.

“As the saying goes, ‘the only thing constant is change.’ It’s likely that changes affecting use of HFCs in container refrigeration will eventually come.”

Carrier’s engineering teams are pressing ahead with research into systems that will tap those next-generation refrigerant alternatives that make the most sense for customers worldwide, always focused on developing solutions that deliver the same or better attributes of performance, compatibility, cost, safety and environmental soundness, as found in today’s R-134a.

“Just as we helped to guide the container shipping industry through the major transition from the ODP refrigerants of the past into today’s standard,” Smith said, “Carrier will be there to lead our customers into the next phase of refrigerant technology.”