Over the nearly two-hundred years refrigerants have been around there have been a variety of types and classifications. In the very beginning in the eighteen-hundreds we started with the simplest, and cleanest, of refrigerants known as natural refrigerants.
These natural refrigerants consisted of naturally occurring elements throughout our wold. These could be carbon dioxide, ammonia, air, water, or oxygen. Also, under this natural refrigerant umbrella were what’s known as hydrocarbon refrigerants. These were your propane, isobutane, ethane, methane, and many more. These refrigerants were the foundation of today’s modern day refrigerant classifications known as Chlorofluorocarbons (CFCs), Hydrochlorofluorocarbons (HCFCs), Hydrofluorocarbons (HFCs), and Hydrofluoroolefins (HFOs).
While most of our everyday refrigerants used today fall into one of the categories we mentioned above there are some outliers that simply don’t fall into the ‘standard’ classifications that we are used to today. In this article we’re going to take a brief look at some of these outliers and what refrigerants fall under them. For a more in-depth guide we will also be producing refrigerant fact sheets on each of these individual refrigerants.
H – Halon/Haloalkane Refrigerants
Halon refrigerants were one of the building blocks of modern day refrigerants we see today. Earlier I had mentioned that natural refrigerants along with hydrocarbons were the very first refrigerants used in the world. Well, the next step towards progress were halon refrigerants.
Now, technically, all of the main refrigerant classifications that we use today such as CFCs, HCFCs, HFCs, and even HFOs can be considered halon refrigerants. But, these classifications are compounds containing one or more kind of halogen. A standard halogen refrigerant is not compounded.
The basic halon chemicals were used primarily as a fire extinguishing agent. In recent years halon is no longer manufactured either due to the toxicity that they can present or due to the detrimental effects on the Ozone.
While I could include every CFC, HCFC, HFC, and HFO in this section I am NOT going to as I have already covered them in broader separate articles. The refrigerants below are the ones that I could not classify into one of those larger groupings:
- R-12B1 Bromochlorodifluoromethane
- R-12B2 Dibromodifluoromethane
- R-13B1 Bromotrifluoromethane
- R-22B1 Bromodifluoromethane
- R-114B2 Dibromotetrafluoroethane
HCC – Hydrochlorocarbon
I had to do some research on this category. There wasn’t much to be said about actual refrigerants. These types of chemicals have a wide range of applications from insulation, fire extinguishing, to pesticides, and all the way to wood varnish.
The one piece of the puzzle I did find here is that R-20 Chloroform was a necessary building block to create R-22. Yes, when chloroform is mixed with hydrogen fluoride we get chlorodifluoromethane, also known as the HCFC R-22. With this knowledge, we can say that HCC refrigerants were an essential in modern day air conditioning and refrigeration.
That being said, there was and still is a lot of concern with HCCs. Depending on the type of chemical within this family the toxicity can be deadly. There are recorded birth defects and other abnormalities. Remember hearing about DDT pesticides? Well, they came from HCCs.
While I couldn’t find a practical refrigerant application for HCCs I wanted to still list them below. From what I have found they were mainly used elsewhere and when they were used as refrigerants it was as a blend rather then a primary application.
- R-20 Chloroform (Trichloromethane)
- R-30 Dichloromethane (Methylene chloride)
- R-40 Chloromethane
- R-120 Pentachloroethane
- R-130 1,1,2,2-Tetrachloroethane
- R-130a 1,1,1,2-Tetrachloroethane
- R-140 1,1,2-Trichloroethane
- R-140a 1,1,1-Trichloroethane (Methyl chloroform)
- R-150 1,2-Dichloroethane
- R-150a 1,1-Dichloroethane
- R-160 Chloroethane (ethyl chloride)
PCC/PFC Perchlorocarbon & Perfluorocarbon Refrigerants
I know I’ve said it already folks, but PCC and PFC are the building blocks of modern day refrigerants. Just look at the name PFC. Take off the ‘per’ and you get the name we are all familiar with, ‘Fluorocarbons.’
Within these categories exists R-10 or Carbon Tetrachloride. This was used as a refrigerant in the early eighteen-hundreds and was a precursor to R-11 and R-12. Along with that other refrigerants within this category have been used in blends to create other refrigerants. As a few examples, R-116 Hexafluoroethane is used to create refrigerants R-508A and R-508B. R-218 Octafluoropropane is used to create R-413A.
Again, I couldn’t find an active record of these being used as refrigerants. Instead,they were used in blends to create other refrigerants that we have all seen before.
- R-10 Carbon Tetrachloride (Tetrachloromethane)
- R-110 Hexachloroethane
- R-14 Tetrafluoromethane
- R-116 Hexafluoroethane
- R-218 Octafluoropropane
- R-C318 Octafluorocyclobutane (Perfluorocyclobutane)
The Olefin Refrigerants
A lot of you may be familiar with Olefin refrigerants already through the most popular classification of hydrofluoroolefins (HFOs). The most common HFO you’ll see today is the R-1234yf which is used in automotive applications. While HFOs may sound new and different if you look at things from a chemistry perspective HFOs are not that different then the HFCs we use today.
Just like their HFC counterparts HFOs contain Hydrogen, Fluorine, and Carbon. The one real difference between these two refrigerants is that HFOs are unsaturated. In other words they have at least one double bond of carbon. These double bonded molecules are known as Olefins or Alkenes. This is where the name Hydrofluroolefins comes from. HFOs may have been around for a while there was never a demand for them. HFCs were the favored refrigerant when CFCs and HCFCs went away in the 1990’s. It was in the early 2000’s that things began to change to favor HFOs.
While you may have all heard of HFOs before chances are you haven’t heard of the other classifications of Hydrochlorofluoroolefin (HCFO), Chlorofluoroolefin (CFO), and Perfluoroolefin (PFO). At this time these newer Olefin classifications are rarely used, but that may change in the future.
Let’s take a look at some of the other Olefin refrigerants:
HCFO – Hydrochlorofluoroolefin
- R-411A (Mixture of R-1270, R-22, and R-152a)
- R-411B (Mixture of R-1270, R-22, and R-152a)
- R-411C (Mixture of R-1270, R-22, and R-152a)
CFO – Chlorofluoroolefin
- R-1112a Dichlorodifluoroethene
- R-1113 Chlorotrifluoroethylene
PFO – Perfluoroolefin
- R-1114 Tetrafluoroethylene
- R-1216 Hexafluoropropylene
- R-1218 Hexafluoropropene trimer
Conclusion
For the most part folks the refrigerants mentioned in this article have either been retired due to environmental or toxicity concerns. The only exception to this rule that I am aware of are the Olefins classification. These refrigerants are still fairly new to the world and have a relatively minimal impact on the environment.