The International Electrotechnical Commission (IEC) is expected to start its final vote on whether to increase the charge limit to 500 g for A3 (flammable) refrigerants in mid-March and conclude in mid-May, according to Marek Zgliczynski, Embraco’s director of research and development, who chairs the IEC SC61C subcommittee.

If passed, the standard would be published in August. Then countries and regions could use it as a reference to enact binding standards.

However, in the U.S., it is widely rumored that the standards bodies that would approve a charge limit increase for hydrocarbons – ASHRAE and UL – may want to limit the increase to 300 g, not 500 g.

That was certainly the understanding of numerous exhibitors at the NAFEM foodservice equipment show last week in Orlando, Fla. But not everyone agreed that 300 g was a sufficient level for the standard.

“We’re hearing it may only be 300 for propane, but that’s not enough,” said Jason Paquette, director of engineering for Structural Concepts, a Muskegon, Mich.-based display case manufacturer. “We need it to go up to 500 g, which would cover 90% of our cases.” The current 150 g limit could handle only 20% of the company’s cases, which include 12-ft-wide open-air refrigerated cases; it is currently collaborating with another manufacturer on some R290 equipment, he said.

The cost associated with R290 charging equipment is considerable, he noted. “That doesn’t scare us, but it doesn’t make sense for only 20% of our equipment.”

On the other hand, Nick Shriner, director of engineering for Winston Salem, N.C.-based OEMs Beverage-Air and Victory, observed that, while a higher charge is needed to use R290 to its fullest capacity, “300 grams would be good enough for our small systems.”

Brandon Marshall, application manager refrigeration for component maker CAREL’s U.S. division located in Manheim, Pa., said he believes 300 g  – double the current charge limit – “is a good first step.” Ultimately, though, a 500-g charge limit “would allow is to expand our compressors to several other applications.”

Robert Bittner, a consulting engineer based in Palm Coast, Fla., who spent 35 years with Ahold/Delhaize subsidiary Giant Food of Maryland, thinks the standard will only go up to 300 g in the U.S. because 500 g would be “too radical.”

He also cautioned that any increase in the U.S., after being approve by ASHRAE, UL and the Environmental Protection Agency, would still need to be adopted by building and mechanical codes, which could take some time.

“Everybody’s dreaming that the building codes are going to change quickly – keep dreaming,” he said. “This involves life safety in buildings, and they’re not going to change quickly.”

“We’re hearing it may only be 300 for propane, but that’s not enough.”

Jason Paquette, director of engineering, Structural Concepts

Want to find out more, or have something to say about this story? Join the ATMO Connect network to meet and engage with like-minded stakeholders in the clean cooling and natural refrigerant arena.