Garden City, Kan. — Chances are pretty good that you don’t spend a lot of time thinking about ammonia refrigeration—even though, as Dallas Babcock was quick to tell me the other day, “If you eat it or drink it, at some point it was probably cooled with ammonia refrigeration.”
We were standing in Garden City Community College’s ammonia-refrigeration teaching lab at the time, surrounded by intricate arrays of color-coded pumps, pipes, and tanks—all of them belonging to four systems for making quantities of ice or chilling big spaces. Mr. Babcock (left) showed me the largest of the college’s machines, a two-compressor behemoth that he called “our monster.” It can freeze 8,000 gallons of water in about five hours.
Why would a college be so interested in making ice? In a word, money.
About 15 years ago, an enterprising Garden City faculty member named Gerald Hundley asked local employers what kinds of programs they’d like to see the college offer. It turned out that the food-processing companies that are the mainstays of the economy here needed training for the employees who operate the mammoth refrigeration systems on which their plants rely. For big companies, Mr. Babcock said, “the difference between operating efficiently and inefficiently can be millions a year in electricity and maintenance.”
In 1996 Mr. Hundley established the first program in the U.S. to teach people how to run ammonia-based refrigeration systems safely and economically. He has since retired, but the college now offers more than 40 weeklong training seminars every year that draw employees of major food processors, breweries, juice companies, and even skating rinks.
Mr. Babcock, an instructor in the program, said that the typical refrigeration-system operator has learned how to run his machines from his supervisors. “For the most part, they don’t know why they do what they do,” Mr. Babcock said. “We give them the tools to go back and learn their systems.”
The thermodynamic properties of ammonia that make it useful for refrigeration have been known, Mr. Babcock said, since the time of the pharaohs, when ammonia was recovered from bat guano. The techniques on which modern systems depend were developed in the middle of the 19th century, and in the early years of the 20th century, the first home refrigerators used ammonia. But because ammonia is dangerous and cannot be used with some common, cheap metals—like copper—ammonia-based systems are costly to produce. Dupont’s development of the chlorofluorocarbon Freon made inexpensive, safe systems feasible for homes.
“Ammonia is always cheaper in the long run” for big systems, Mr. Babcock said, and the realization that chlorofluorocarbons may be linked to global warming has prompted renewed interest in ammonia systems. As companies have realized that spending a little to train the employees who run the systems can bring big savings, competing training programs have sprung up. Several are at other community colleges around the country, Mr. Babcock said, while another, run by a Garden City Community College ammonia-refrigeration alumnus, is right here in town.
Still, Mr. Babcock said, the college’s classes are full. About a dozen students every week spend their mornings studying science in a seminar room and their afternoons in the lab making ice—and, if they’ve been paying attention, saving money.