ACHRNEWS

Changes Lead Back To The Basics

October 29, 2004
With a flurry of conversations involving a seemingly endless array of refrigerants, a European trade association is urging a back to the basics consideration.

Frankfurt, Germany-based Eurammon wants ammonia to stay on the list - and at a pretty high position.

"For today and the future, the [use of ammonia] is indispensable for providing mankind with necessities," the organization said in a document familiar to the industry but still timely.

"Since the invention of the refrigerating machine in the past century, large refrigerating systems in the food, beverage, and chemical industries have predominately been built for ammonia," the report said. "And even today this is still the case.

"It is a fact that ammonia, in comparison to other substances, can serve its purpose with by far the least consumption of energy. Nearly all over Europe excellent experiences have been gained with ammonia: breweries, slaughterhouses, and large freezing plants.

"Therefore, it is surprising that competing substances could ever challenge its position as a refrigerant."

The association then ticked off possible reasons ammonia could garner less than favorable reviews, such as safety issues because of its toxic nature, the lack of strong lobbying efforts, limitations for its use as systems get smaller, and different skills needed to work with the piping for ammonia systems rather than the more common copper piping.

A Second Wind

The demise of CFCs and HCFCs is inviting a revisiting of ammonia in a more favorable light, the report said.

First, it is argued that ammonia is a natural refrigerant that has neither ozone depletion nor global warming potential.

The safety issue is really of "only a minor risk potential." Here, the report notes, "Each human being transpires 17 grams of the substance a day. Only 3 percent of the ammonia existing on this planet results from human activity even though it is produced in large quantities for fertilizers. Ammonia is readily soluble in water."

The fact that ammonia emits an odor can be an advantage, the report argues. "Even the slightest traces of ammonia in the air can be perceived easily. Refrigerant leakage is therefore detected at once.

"Actually, even among persons who are used to relatively high concentrations of ammonia due to their work, not a single case of lasting disease has been reported over an observation period of several generations."

A Cautionary Note

But the report does stress that ammonia should be treated with care. "There is no reason for a thoughtless handling of ammonia," the report said. Further it noted that those handling ammonia must be aware of the concern the refrigerant creates among laypersons. Such persons "could panic if suddenly exposed to the smell," even though lasting negative effects of such contact more than likely will not pose a danger.

An additional "handle with care" directive: "Increased attention is required to prevent liquid ammonia from getting into sewage or ground water."

A Difference

Ammonia is identified as a natural refrigerant. But ammonia advocates also point out that it is different than other natural refrigerants such as propane and butane, in the fact that ammonia does not have the potential for explosions.

"In a compound with air, ammonia is ignitable only within a very narrow span of concentrations - and this only in combination with high ignition energy.

"Therefore, fears of explosions are unfounded. In this respect, ammonia differs substantially from the other refrigerants under discussion such as propane and butane."

A Good Neighbor

Ammonia leaks can generate news among local media, especially while ammonia tanks are being transported by truck or train and an accident occurs resulting in a leak near a residential area.

"As for any technical system, unforeseeable emissions cannot be completely ruled out," the re-port said. "Except for a temporary irritation by bad smell, no further consequences need to be feared. Gaseous ammonia is considerably lighter than air. Therefore, it ascends very quickly to higher atmospheric layers, similar to visual smoke. There it decomposes within a few days. The released nitrogen is washed out by the rain and spread out as a fertilizer in the ground."

Politically Correct

A key point of advocates of ammonia encompasses its energy efficiency potential when used in properly designed mechanical refrigeration systems. And that goes along with its zero ozone depletion and zero global warming potential.

The report said, "Without a doubt, by using ammonia, refrigeration can be realized with the least possible energy requirement. In this respect, the endeavors to reduce the global greenhouse effect can also be best supported with this refrigerant."

The report went on to say that new technologies are further showing ammonia in a favorable way.

"In comparison to existing old systems, modern ammonia systems are designed for clearly reduced refrigerant charges. They correspond to ideas which do justice to today's environmental awareness."

For more information, visit www.eurammon.com.

Publication date: 11/01/2004