The standards committee of the International Institute of Ammonia Refrigeration (IIAR) has begun work on a safety standard for hydrocarbon refrigerants in commercial and industrial applications, including chillers and heat pumps.
Though traditionally focused on ammonia, IIAR “is fully capable of developing ANSI-approved standards safety standards for hydrocarbons,” said Bruce Nelson, president of Colmac Coil Manufacturing, and chairman of an IIAR task force that looked into developing a hydrocarbon standard last year. “A hydrocarbon safety standard – which is needed and missing – fit’s our mission to make the world a safer place.”
(IIAR has also developed a new safety standard for CO2 systems, which is out for public review.)
Nelson, who is the new IIAR chair, gave an update on the hydrocarbon standard at the IIAR Natural Refrigeration Conference & Expo in Phoenix last week. He said the standard work was “underway.”
The IIAR standard is officially known as “Design, Installation, start-up, Inspection, Testing and Maintenance of Closed-Circuit Hydrocarbon Refrigeration Systems.” The standard will focus on commercial and industrial applications used in engine rooms or outside facilities, “where ventilation and the lower flammability limit can be controlled,” said Nelson.
Few centralized propane systems exist in North America. One example is Whole Foods Market in Santa Clara, Calif., that has been testing a propane/CO2 system.
“A hydrocarbon safety standard – which is needed and missing – fits our mission to make the world a safer place.”
Bruce Nelson, IIAR chair
The IIAR board approved the formation of subcommittee to work on the hydrocarbon standard last August. Joseph Pillis, director of engineering, industrial refrigeration for Frick, will serve as the subcommitee’s chairman.
The hydrocarbon standard subcommittee will evaluate existing standards, especially those in Europe,” said Pillis.
Because ASHRAE already has a design standard for hydrocarbons, IIAR will be working with ASHRAE’s Standard 15 committee “to determine current gaps in their design standard,” said Dave Rule, president of IIAR, in an interview last year.
Rule noted that the hydrocarbon standard would not address low-charge (150 g or less) commercial display cases or residential refrigerators. Those “are considered to be covered under UL standards,” he said.
An application to the Environmental Protections Agency asking the agency to legalize the use of propane in rack systems is “85% done,” said Keilly Witman, owner of KW Refrigerant Management Strategy and former manager of the EPA’s GreenChill program.
In terms of a charge limit for rack systems, “EPA like to incorporate industry standards,” Witman said. The IIAR hydrocarbon subcommittee will be looking at including a charge limit in its standard, Nelson said.
Nelson ranked hydrocarbons highly as a refrigerant, pointing it that it is very efficient. He cited ASHRAE statistics that listed propane (R290) as having a COP (coefficient of performance) of 5.987 in a refrigeration system at 20°F evaporating and 86°F condensing, just below ammonia’s COP of 6.254, and higher than the COPs of R507A (5.564) and R744 (3.514).
Nelson said the price point and ROI for hydrocarbon systems are better than those for ammonia and CO2. “In my opinion, hydrocarbons are the only natural refrigerants that meet or beat F-gases on first cost and energy efficiency combined,” he said.
Another advantage of hydrocarbons is their low liquid density, said Nelson. “They have about half the liquid density that HFCs do. So for the same amount of work, you use half the charge.”
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