The following was the keynote address delivered by Milton Garland at the 1997 International Institute of Ammonia Refrigeration (IIAR) Annual Meeting in New Orleans, LA. Mr. Garland was active in the ammonia refrigeration industry for over 75 years. Hired by the Frick Co. in 1920, he worked at the Frick plant of York Refrigeration, Waynesboro, PA, until June 2000. He was an inventor who held over 40 patents. Mr. Garland died in July 2000 at the age of 104.

Ammonia (NH3) was first isolated in the year 1761 by Joseph Priestly. While ammonia and carbon dioxide (CO2) were known as possible refrigerants, it was a matter of 73 years before anyone came up with the workable compression refrigeration cycle, which occurred in 1834.

A U.S. engineer, Jacob Perkins, first wrote about the closed compression refrigeration cycle. In that same year, a man by the name of Hoben, who apparently worked closely with Perkins, took out a U.S. patent. That patent outlined the Perkins system and featured the ammonia expansion valve. His patent covered the need for close control of the refrigerant into the evaporators.

Ammonia was a natural refrigerant. We had 73 years of people searching for a way to harness a refrigerant, and now, in 1859, we had an outline of how to harness that refrigerant. In 1859, a gentleman in France — Carré — built the first ammonia water absorption system.

By 1860, refrigeration applications in all areas were underway to a great extent. Ammonia was the natural refrigerant for those applications. Consider the fact that people engaged in the slaughtering industry required refrigeration. Also, consider the fact that ammonia was made from all of the waste material. Ammonia was, therefore, a very natural fit. They needed refrigeration. They could produce ammonia. So, ammonia really became the natural refrigerant for the meat industry.

Developing Property Tables

This brings us to the question of what kind of ammonia property table was available at the time. How was it that they knew thermodynamic properties? In my search, the best I could find is that the first properties were issued for sale to the public around 1858. When I was in college in 1916, Professor Goodenough of the University of Illinois put together tables for steam and ammonia. The University of Illinois also put together aqua-ammonia tables for the use of those who were designing ammonia water absorption systems.

It was rather unfortunate that the various tables did not agree. The American Society of Refrig-eration Engineers (ASRE) was greatly concerned about this matter. ASRE petitioned Congress, which authorized the U.S. Bureau of Standards in 1921 to investigate and publish accurate tables for the use of the rapidly growing refrigeration industry.

The U.S. Bureau of Standards published the first property tables in 1923. Three years later, ASRE published a data book titled Thermodynamic Properties of Refrigerants and Brines. It carries a note which says that three years of experience with the tables produced by the U.S. Bureau of Standards has proven their accuracy and they will remain accurate tables for all time to come.

I also wish to point out that the production of ammonia from the waste of slaughtering continued until the mid-1920s. The first cylinders of ammonia that I handled in 1920 bore the name “Armour and Company.”

About the same time, the magazine Ice and Refrigeration had an article saying that a low-cost material had been discovered which would enable the synthetic production of ammonia. Sure enough, from the mid-1920s on, ammonia cylinders no longer bore the name “Armour and Company.” Instead, other companies that put NH3 together synthetically now marked the cylinders.

We are now up to World War II. Ammonia served our country very well. In fact, early preparations for World War II in 1940 started with gun firing rooms refrigerated to -10°F with an ammonia system. There were no questions about operations at room temperatures, but there were certainly a lot of questions about the lubricants used on an army tank that were simply not suited for -10°.

We had to delay the test run for a month until they could get lubricants for the engine and the treads of the tanks that would be successful at the -10° level. Larger rooms for larger guns were built at -20°, followed by rooms at -75° for the testing of small arms and ammunition.

Ammonia systems stood up very well to the tremendous concussion of some of the larger guns. Never did I hear any complaint about leakage. Minus 75° applications were readily made because of experience with ammonia and technology already available for freeze-drying systems at -75° used in the production of penicillin.

All of the special installations, like the many new powder plants and the preparation of ballistic material for rockets, for the most part, were ammonia, and all were highly successful. A -75° application required ammonia at -90° in a three-stage system.

Some of the very special things we did included the production of artificial rubber. Artificial rubber was going to be produced in five plants built by the Rubber Reserve Corp. These plants required an accurate control of the reaction temperature of the materials being mixed to produce the rubber latex.

Unfortunately, all five of the original installations failed because the refrigeration was inadequate. This was a rather unusual situation because the Rubber Reserve Corp. issued a letter to the various manufacturers stating that they would supply a reactor for the exclusive use of each of those who bid on the work.

The reactors were pressure vessels, but we were restricted to absolutely no changes. The reactor was about 14 ft in diameter, 14 ft high, and the only internal access was a standard steam boiler manhole opening. Evaporators would have to be built in pieces to go through that manhole opening. There were two available sleeves for pipes in and out.

The ammonia application won the contest, and ammonia was applied in all artificial rubber production plants throughout the war and for many years thereafter.

Safety in Operation

In thinking about what I might say regarding ammonia, it occurred to me to mention the tremendous safety in operation of ammonia, particularly with the unskilled people who were asked to take over the operation of refrigeration equipment. A -75° engine testing plant required both the room temperature to be at -75° and the air for the engine to be chilled to -75°, without any interruption in operation, for 24 hours or more.

Looking back, we had a one-week operating test demonstration. The man they supplied was a 20-year-old miner who went to work in a coal mine at 16. He was unfit for the Army because of a physical handicap, but he was the man supplied to take over this operation. This caused me to think of the years ahead when we installed plants.

During that one week of test operation, the people who were going to take over were really, for the most part, inexperienced with ammonia. And yet, that highly complicated three-stage ammonia system and the very special dual set of coils, since there was no stoppage for defrosting, was just a matter of changing over at the right time to continue that air at -75°.

Ammonia commands respect, and ammonia has received that respect. Consider the fact that from 1834 up until the late 1920s, the majority of all refrigeration applications used ammonia.

Naturally, since ammonia was available, refrigeration was put into hospitals, sanitariums, hotels, and was used for air conditioning. Literally thousands of those installations were considered safe operations until after World War II.

Ammonia is the friendly refrigerant. Why friendly? Consider the fact that immediately following World War II, fishing boat owners discarded refrigeration systems that did not use ammonia and installed systems using ammonia. A captain of one of those boats mentioned to me, “Look, we’re never going to lose a cargo of fish with ammonia, because from myself on down, if we smell a leak, we’re going to do everything to stop it. We’re never going to get caught out at sea with a boat load of fish and no refrigeration.”

This had happened to them before because of undetected leaks. Then they had a shipload of fish and no refrigeration.

We must never overlook the fact that ammonia is the only refrigerant with a density less than one. All of the other refrigerants have a density much greater than one. If you can picture the compression refrigeration cycle, the only thing that moves the refrigerant is the compressor.

Ammonia, which requires the movement of less than one-half pound per minute, is the most efficient refrigerant. Any other refrigerant will require the movement of slightly over two-and-one-half pounds per minute per ton of refrigeration. Ammonia has been, and always will be, the refrigerant of highest efficiency.

My check of usage points out that for about 160 years, people have been using ammonia in all of their test work and then the building of installations. The safety and the efficiency of ammonia are remarkable. Ammonia has been, and will always be, the most efficient refrigerant available.

Sidebar: ARTI Is (Already) Looking Into the Industry’s Future

ARLINGTON, VA — The hvacr industry, which experienced evolutionary change until the early 1990s, is continuing to undergo a period of unprecedented transformation. The pressures driving these changes — protection of the outdoor environment and conservation of natural resources — will only become more pronounced in the future.

In response to this challenge, the Air-Conditioning and Refrigeration Technology Institute (ARTI), headquartered here, is spearheading a government-industry collaboration whose mission is to “identify, prioritize, and undertake precompetitive research that focuses on decreasing energy consumption, increasing indoor environmental quality, and safeguarding the environment.” ARTI calls this its 21st Century Research (21-CR) program.

According to program director Glenn Hourahan, P.E., the emphasis of the 21-CR program is to undertake research “that will help the hvacr industry commercialize equipment and services in the next decade that, once integrated into building and process applications, will utilize dramatically less energy than today’s applications while addressing the comfort and indoor environmental quality (IEQ) needs of building occupants.”

Some of these energy and IEQ improvements will accrue by innovative advancements in the hvacr equipment itself, noted Hourahan.

Other benefits, he said, will be garnered by better incorporation of improved equipment into more comprehensive systems for particular applications, such as buildings or refrigeration processes.

“The effort seeks to foster an environment where technical barriers are identified, solutions investigated, and information shared,” said Hourahan. “The effort undertakes precompetitive research that focuses on resolving technological hurdles and difficulties that prevent or impede manufacturers from commercializing next generation systems and components. Once these technical challenges have been addressed, the various stakeholders are positioned to apply the 21-CR research units and to produce the products/services that satisfy market needs within the hvacr sector.”

The five focus areas of the 21-CR program are:

  • Alternative equipment (investigations of hvacr cycles other than today’s fluorocarbon vapor compression cycles);
  • Higher efficiency equipment (improved heat exchangers, motor systems, compressors, controls and sensors, air handlers, testing, diagnostics, pumps and pump controls, etc.);
  • System integration (improved distribution systems, zone control, waste heat recovery, integration of envelope and lighting with mechanical systems, advanced controllers, communications, etc.);
  • Indoor environmental quality (enhanced control of temperature, moisture, indoor contaminants, ventilation, etc.); and
  • Environmentally friendly working fluids (refrigerants, lubricants, secondary heat transfer fluids, eutectics, process fluids, etc.)
  • For a complete list of 21-CR projects currently underway, go to

    Sidebar: Over the Years…

  • 1927
  • In California, Golden Gate Motor Transportation Co. became the first trucking firm to use mechanical refrigeration in its trucks and trailers (both of them).

  • 1933
  • The National Recovery Act required all industries to establish codes of fair practice, stimulating existing associations or newly created ones to draw up such codes and get their industries’ compliance with them.

  • 1937
  • Peerless Ice Machine Co. of Chicago changed its name to Peerless of America, Inc., developed a new evaporative condenser with one moving part, and produced a spinner-type finned cooling unit for General Electric refrigerating units.

  • 1938
  • The American Society of Refrigerating Engineers and the American Society of Heating and Ventilating Engineers adopted a code of minimum standards for comfort air conditioning.

  • 1940
  • A Lincoln, NE, women’s apparel store boosted perfume sales by adding scents to the air conditioning system.

    Publication date: 04/30/2001