The following article was published in the ASHRAE Journal - Industry News,
May 2002. © 2002 American Society of Heating, Refrigerating and
Air-Conditioning Engineers, Inc.
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IIAR Sees New Role For Old Refrigerant

An old hand in refrigeration likes to say that everything old is new again. An example is carbon dioxide, a refrigerant that is returning to favor, some 70 years after it was replaced by CFCs in most applications.

A group of 64 people met March 9 before the 2002 annual meeting of the International Institute of Ammonia Refrigeration (IIAR) to organize a new committee to develop and disseminate information on the use of CO2 in conjunction with ammonia in "cascade" systems for low temperature refrigeration applications.

Such systems, which are already being used in Europe, minimize the charge required for NH3-only systems, and can be designed to keep NH3 in a machinery room away from occupied production areas.

Rudy Stegmann, Member ASHRAE, says the systems are similar in cost to install, since the volumetric capacity of CO2 allows for smaller compressors and piping on the low side. Also, the cost of CO2 is much lower than ammonia, which is a significant issue for large plants.

Another important issue, he said, is that many owners can reduce the total charge of the ammonia below the 10,000 pound (4.5 Mg) threshold for OSHA and EPA process safety regulation. "This (technology) will let a lot of small plants cut their charge in half, and avoid burdensome regulations."

The new IIAR Ammonia/CO2 Committee hopes to complete work on a draft of a design manual by next spring, said committee Chairman Jim Shepherd, Member ASHRAE. The Committee also will work to modify ANSI/ASHRAE Standard 15, Safety Standard for Refrigeration Systems.

"Right now, industry codes do not adequately cover cascade systems," said Shepherd. "This is something we have to address. There is also concern about recent patents."

MORE THAN 950 people attended this year's IIAR annual meeting, the 24th. IIAR was founded in 1972 by 48 people, including many ASHRAE members, to promote the safe use of ammonia for refrigeration. Today, IIAR's membership of 1,400 plus members consists largely of end-users(49%), followed by contractors (22%), and manufacturers (13%).

IIAR's mission of "education and advocacy" was reflected in the annual meeting program. This year there were several keynote and plenary speakers, six panel discussions, two "chat Whitehall expert" sessions, 11 technical paper presentations, a "problem-solution" session, and an exhibition with 98 exhibitors. Notable among the papers was "Sizing and Design of Gravity Liquid Separators in Industrial Refrigeration" by Brent Wiencke of Nestlé USA.

"It's taken me 30 years to learn what he's presenting in a single paper," said Forbes Pearson, Ph.D., an international refrigeration expert. "Everything is covered. It is excellent work."

Additional papers were presented on the design of a large ammonia/CO2 cascade system for a new food plant, and conversion of an existing R-22 refrigeration plant to an ammonia/CO2 cascade system.

THE NEW IIAR chairman is Morris Eisert, vice president of design and sales for American Industrial Refrigeration Eisert says he hopes to expand IIAR's educational activities and to work with industry partners to attract younger people into the refrigeration industry.

"All of us in this trade are facing the challenge of recruiting young people," he said. "We need to institute more programs at the high schools and trade schools to attract good people to our industry."

Back Row (Left to Right): Kent Anderson, Ron Strong, Bob DeVillez, Andy
Pearson, Gary Dunn, Larry Basel, David Grong, Steve McLeod, Nasser
Karimzadeh, Brian Marriott, Front Row (left - right) Bill Bowles, Rowe
Bansch, Rudy Stegmann, Holm Gebhardt, Morris Eisert, Ron Vallort, Bob St.
Jean, Jeff Welch, Don Stroud (Not Pictured: Fred Herl)