Though often confused, R20 and R22 are very different refrigerants. R20 is very rarely used as a refrigerant in modern times. Instead, it is used as a precursor for R22. Following is a brief guide covering these two chemicals, their history, their uses, and their differences.
R20 is the label given to chloroform by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers(ASHRAE). Each refrigerant is given an R number by ASHRAE depending on the molecular structure of the chemicals involved.
R22 is the ASHRAE label for chlorodifluoromethane, which is produced using chloroform. Chlorodifluoromethane is referred to as Freon when manufactured by the Chemours Company. Freon is currently the most widely used refrigerant on the planet.
History Of R20
Chloroform has a short, yet powerful history. The chemical has seen several uses over the years. Some of them were for medical purposes while others involved criminal intentions. Today, the most common use of the R20 chemical is for producing the R22 refrigerant. More than 90 percent of all chloroform synthesized is used specifically in the production of refrigerants.
The synthesizing of chloroform began around the 1830s. It’s believed that Frankfurt was among the first to produce the chemical by mixing together chlorinated lime and ethanol. A year later, Samuel Guthrie recreated the results in New York and noted the mixture had anesthetic properties. Both of these professionals believed at the time that they had produced chloric ether rather than chloroform.
Major strides in the understanding of chloroform began in the 1850s after James Young Simpson discovered the sedative effects of chloroform. He realized that the chemical could be used to put patients to sleep nearly instantly without causing any of the negative effects that are associated with ether.
The Uses Of R20
It wouldn’t be long after Simpson’s discovery that chloroform would become the most widely used sleeping aid in hospitals across the globe. It was used for treating soldiers during wars and for mothers who were giving birth. And, of course, criminals would begin to use it as a tool to murder and rob with ease.
Chloroform would slowly see less use in hospitals, but increased use in other applications. It became a common ingredient in pesticides across the globe thanks to its properties as a solvent. It could also be used as a fumigant, a cleaning agent, and even in fire extinguishers. Chloroform is also widely used as a precursor for the manufacturing of Teflon, which is found on cooking utensils, pipes, and on surgical equipment.
The largest use of chloroform was in the production of the chlorodifluoromethane hydrochlorofluorocarbon(HCFC), otherwise known as R22. Though, even the use of chloroform in the production of refrigerants has slowed down tremendously in many parts of the world. Many developed countries have banned the use of HCFC refrigerants, particularly R22, and thus chloroform is also seeing reduced production.
The History Of R22
Refrigeration technology had been evolving rapidly prior to the introduction of R22 to the market. The major problem at the time was that refrigerants were often dangerous to man and to the environment. Many of them were flammable and highly toxic. During the time of the discovery of R22, ammonia was among the most popular refrigerants.
Researchers working for General Motors were determined to find a safer solution to their refrigerant needs. They began to produce chlorofluorocarbons, which are hydrocarbons that typically contain carbon, fluorine, and chlorine. Some of the first chlorofluorocarbons used for refrigeration hit the market in the early 1930s, almost 100 years after chloroform began to be synthesized. The first products were labeled as R12.
It wasn’t long before R22 was developed and it took the market by storm. It would become the go-to refrigerant for residential use across the country. The r 20 refrigerant and the shift to blue also spread to other countries as well. It was cheap to produce, and it seemed to have no negative impact on anything. As a matter of fact, there was very little that R22 interacted with.
The Dangers Of R22
For a long time, experts thought that R22 was a completely safe refrigerant. Their opinion changed after they realized that the hydrocarbons were interacting violently with UV rays from the sun. The ultraviolet light caused the chemicals to break down and what remained damaged the ozone layer.
In 1987, the Montreal Protocol was passed in an attempt to protect the ozone layer by reducing the production and usage of substances that had ozone depleting properties. 197 different countries agreed to the terms of the Montreal Protocol. The protocol has been amended several times and has since put a time limit on the remaining production and usage of HCFC products. In the United States, homeowners will no longer be able to use R22 refrigerant after January 1, 2020.
Knowing that R22 will eventually be phased out, experts across the globe have been working to develop a new, safer alternative. There have been many great strides in refrigerant development. It is widely accepted that R-410A will be the new refrigerant used in most residential applications.
The major problem is that homeowners will need to replace much of their equipment to use this new refrigerant. Other solutions, like TdX 20, can be used with same equipment, thus saving the homeowner a significant amount of funds.
A Final Comparison Of R20 And R22
R20 and R22 do have much in common concerning their molecular structure, but that is where the similarities start to end. Though R20 is listed as a refrigerant by ASHRAE, it is very rarely, if ever, used as one by itself. Instead, it has been used in the production of chlorodifluoromethane, which is otherwise known as R22. By itself, chloroform saw most of its use as a sedative during the 19th and 20th centuries.
Today, much is understood of the dangers of chloroform as well as of R22. Both are experiencing constantly decreasing production and use in developing countries.
