Why Do Available Refrigerants Change?
EPA 608
Why do available refrigerants change?
Refrigerants are a relatively new discovery. As late as the WWII era, ice was still used in many communities as a way to preserve food or for air conditioning. As the invention of the refrigerator and industrial freezers became more commonplace, the ability to scale down the process became more available.
One of the main components of any refrigerator or freezer system is the use of liquid/gas refrigerants (often called freon by the layman). Various refrigerants use various different elements in order to cool efficiently. However, when the discovery of the OZone depletion - the measurement is known as ODP - many refrigerants had to stay under a certain measurement of OZone depleting measurements. In addition, greenhouse gas emissions - known as GWP or Global Warming Potential - also become a real concern to assess. Both of these have an effect on how today’s refrigerants are stored, processed, and invented.
One other factor that plays into the availability of refrigerants is the danger to users. In the 1920s and 1930s, as refrigeration and air conditioning was in its infancy, there were no guidelines for the safe use of refrigerants. Many companies or industries used dangerous chemicals that would often be able to kill anyone who came in direct contact with them, or even highly flammable chemical mixes. There are many tragic stories of accidents happening because of refrigeration leaks in both HVAC industries, industrial settings, and other various industries.
The Main Types of Refrigerants
HCs / hydrocarbons. The first refrigerants. HCs are essentially pure hydrocarbons. There are two types of hydrocarbons: aliphatic and aromatic. To give you an idea of the danger, some aromatic hydrocarbons are propane, butane, and methane. Not only did some of these smell horribly bad, they were highly flammable and dangerous. Alkanes aren’t any better.
While some are concerned that their RV refrigerators use propane as a refrigerant, the process is slightly different and uses the propane as a fuel to heat up the refrigerant (often ammonia) which is rapidly cooled. Modern air conditioning systems do not run on HCs.
CFCs / chlorofluorocabons. These types of refrigerants are some of the earliest regulated chemical mixes. While not harmless, they were significantly better than many in the past. In the mid 80’s it became publicly apparent that many chemicals were also causing damage to the OZone and a new measurement was created; ODP or OZone Depletion Potential. New refrigerants had to meet a certain ODP measurement before being released. Because of this many CFC refrigerants like R-11 and R-22 were quickly phased out. Once reaching the stratosphere, the compounds become stable and can cause ozone displacement or damage.
All CFC contain chlorine which is also very dangerous when exposed to moisture. Chlorine has been used in warfare as well as cleaning surfaces from biological contamination. Human exposure to any chlorine gasses is never a good thing.
HCFCs / hydrochlorofluorocarbons. These are similar to CFCs but with the addition of a hydrogen molecule. It can still cause significant damage as the chlorine is still present so damage to the stratosphere is still possible yet it breaks down much more quickly than their CFC predecessor. Only recently (January 2020) has the production of the HCFCs become regulated. R-142b and R-22 refrigerants are very common and still in use. As part of the Environmental Protection Agency’s guidelines parallel to the Montreal Protocol, HCFCs are gradually being phased out for more environmentally friendly alternatives.
HFCs / hydrofluorocarbons. Very heavily used in today’s refrigeration and air conditioning systems. HFCs lack that chlorine chemical that is destructive to the stratosphere. They still aren’t perfect. They have a high GWP. Basically, smog is created in the troposphere and the sunlight is reflected back into the atmosphere causing the air to get warmer. The sunlight isn’t as rapidly absorbed by the ground or water and dispersed. Essentially, HFCs are greenhouse gases.
There are still very good refrigerants and with proper handling are relatively environmentally safe. Common refrigerants like R-134a and R-410a fall into the HFC category.
HFOs / hydrofluoroolefin. As I am writing this article, HFOs are considered the safest, best, and newest refrigerants. All HFOs are new to the market and the refrigeration industry is catching up at a rapid pace. R-1234yf and r-454b are leading the way with Low ODP and Low GWP. When released into the atmosphere they are unstable and break down in a matter of days - HFCs break down over years. HFOs still produce trifluoroacetate, so the life of HFO refrigerants may be a short one.
So, What’s The Point Of Knowing This?
Well, usually it’s just good study material for our shameless EPA 608 and EPA 609 course promotion offered at thetrainingcenter.com.
But also, it’s a great way to read about the differences and changes that are currently happening with a good, historical context. As these refrigerants change, so do the machines - mainly heat pumps and air conditioners - that are operated. A machine running an HFC like r-410a (found in most current production heat pumps in 2022) can not run HFOs like r-1234yf. Why? Well… That’s too much to write down here. Keep checking for new updated articles relating to this topic. Basically, the condenser is unable to run the varied types of refrigerant and the energy efficiency would be nominal at best. Each refrigerant blend has its own boiling point and air conditioning units are specifically designed for that liquid/gas mix. There is no retrofitting an older system cooling system with new equipment. With upcoming phase out changes, homeowners researching new hvac systems deserve to be well informed.
Next time your HVAC installer tells you the HFCH air conditioner or compressor they’re trying to sell you is ‘top of the line’ you can tell them to put it back in their warehouse for another 30 years. In the words of NBC, “The More You Know”.