Stay Away from Unapproved Flammable R22 Substitutes

At the risk of sounding like a broken record, I am once again talking about the dangers of unapproved, highly flammable R22 substitute refrigerants which are still easily available over the internet to anyone who wants to buy them. A quick Google search for R22 replacement refrigerant will list several places to buy these dangerous mixtures. The manufacturers market these under a variety of names. The EPA has listed many of them as specifically NOT approved for use. They include refrigerant products sold under the names R-22a, 22a, Blue Sky 22a refrigerant, Coolant Express 22a, DURACOOL-22a, EC-22, Ecofreeez EF- 22a, Envirosafe 22a, ES-22a, Frost 22a, HC-22a, Maxi-Fridge, MX-22a, Oz-Chill 22a, Priority Cool, and RED TEK 22a. The main component of all of these is propane.
 
It is true that the EPA has approved some flammable refrigerants for use in new systems with  lot of restrictions. However, the allowed use is for small refrigerators. The total allowable amount is very small, the systems must be new and specifically designed for flammable refrigerant. Refrigeration systems designed for flammable refrigerant meet strict safety standards, including non-sparking controls and labeling.  Class 3 flammable refrigerants are specifically NOT approved for use as a retrofit refrigerant for R22, or any other system designed for non-flammable refrigerant.

Every time a contactor or relay opens or closes they make a spark which is hot enough to ignite a flammable gas. If someone is losing refrigerant, their system has a leak. Continuing to add a flammable refrigerant on top of R22 will eventually create a flammable mixture. More worrying is that the flammable mixture will be leaking out somewhere.

As a practical matter, most recovery units are not designed to handle flammable refrigerants. Master Cool has just come out with one that is  specifically designed to safely handle flammable refrigerant. Even if you did not use any flammable refrigerant, are you certain that someone before did not add one of these flammable substitutes?

Here is a copy of some of the text from the EPA ruling

“ For retrofit residential and light commercial AC and heat pumps— unitary split AC systems and heat pumps, EPA is listing as unacceptable, as of January 3, 2017:
• All refrigerants identified as flammability Class 3 in American National Standards Institute (ANSI)/ American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard 34–2013; and
• All refrigerants meeting the criteria for flammability Class 3 in ANSI/ ASHRAE Standard 34–2013. These include, but are not limited to, refrigerant products sold under the names R-22a, 22a, Blue Sky 22a refrigerant, Coolant Express 22a, DURACOOL-22a, EC-22, Ecofreeez EF- 22a, Envirosafe 22a, ES-22a, Frost 22a, HC-22a, Maxi-Fridge, MX-22a, Oz-Chill 22a, Priority Cool, and RED TEK 22a. “

Here is a link to the EPA ruling banning flammable refrigerant as a retrofit refrigerant. https://www.gpo.gov/fdsys/pkg/FR-2016-12-01/pdf/2016-25167.pdf

What is an HFO?

Hydrofluoroolefins, HFOs, are a relatively new class of low global warming potential refrigerants. They are actually composed of the same chemicals found in an HFC: hydrogen, fluorine, and carbon. If you define an HFC as a chemical containing those three elements, then HFOs are actually HFCs. The difference is in how they are constructed.

Ethane

HFC 134a

 Both HFCs and HFOs start out as a hydrocarbon, containing a chain of carbon atoms surrounded by hydrogen atoms. To make a traditional HFC you replace some of the hydrogen atoms with fluorine atoms. Standard hydrocarbon molecules and traditional HFC molecules are composed exclusively of single atomic bonds. You can think of an atomic bond as a type of Velcro strip holding the atoms together. Carbon has four atomic Velcro strips while hydrogen and fluorine just have one. Single bonds just attach one strip between atoms. Using only single bonds a carbon atom will connect to four other atoms because it has four bonds. Molecules constructed this way are called saturated. They have the maximum number of atoms joined together.

Propane

HFO 1234yf

What makes HFOs different is that they use a double bond between two carbon atoms. These two caron atoms are connected together with two Velcro strips instead of just one. Since carbon atoms only have four connections, using two to connect to each other means that each carbon can only connect to two other atoms besides each other. This reduces the total number of atoms that can be connected together. This type of molecular construction is called unsaturated.

Why does this make a difference? Unsaturated molecules are far less chemically stable and tend to break down easier. Since HFOs are less chemically stable, they do not survive long in the atmosphere – and so they do far less harm than the more stable saturated HFCs. The difference is dramatic. HFC 134a has a GWP of 1430 while HFO-1234yf has a GWP of 4.

However, HFOs have a design challenge to overcome: they are mildly flammable. The very instability that reduces their GWP increases their flammability. At present, building codes in the US generally do not recognize a difference between highly flammable refrigerants and mildly flammable ones. Most building codes do not allow the use of significant amounts of flammable refrigerant inside the building. ASHRAE is working on revising their Safety Standard for Refrigeration Systems,  Standard 15. It is projected to be ready by January 2018. For more information on the work being done on flammable refrigerants check out this article in Contracting Business
http://contractingbusiness.com/refrigeration/codes-preparing-technology-refrigerant-changes

Substitute Refrigerant Safety

As R22 prices increase and R22 availability decreases, many technicians have at least thought about using a substitute refrigerant in place of R22. Usually, we are looking for a drop-in which can be used to charge a system instead of R22. My primary consideration is safety. Of course I want any substitute refrigerant to work well and be environmentally friendly, but most of all, I want it to not hurt me or my customers. The refrigerant manufacturer should be able to show that their refrigerant is listed on the EPA SNAP list of acceptable replacement refrigerants. If they can’t, I would not use it. Another source of safety information is the required MSDS sheet. Any chemical sold in the United States must have an MSDS sheet. If the seller cannot provide an MSDS sheet, I would not consider using the refrigerant. The MSDS sheet will list important information such as toxicity and flammability. One replacement refrigerant that is advertised on the internet has enough information on the MSDS sheet to let me know I don’t want any part of it. The proper shipping name is “Petroleum Gasses Liquified.” Other statements include “Vapor may ignite if exposed to static discharge", and "Flammable vapor may form if allowed to mix with air. Accumulation of gas is an ignition hazard. Vapors are heavier than air and may travel to an ignition source." R22 systems are not built to operate safely with a flammable refrigerant. There is no way I would put this in a system designed for R22. Last year technicians were killed while working on refrigerated shipping containers that exploded.(See post about it). They were R22 systems which had been charged with a flammable substitute refrigerant. Although the EPA has recently approved the use of flammable refrigerant in limited charge applications, it is important to note that there are many requirements a system must meet to be safe with flammable refrigerants. R22 systems meet none of these. For more information on flammable refrigerants, take a look at my previous post on Flammable Refrigerants. For more information on R22, take a look at my previous post on R22 Conversion. A couple of simple rules to follow will help keep you safe. Can you buy the refrigerant at your local wholesaler? If you can only get it over the internet or from a guy at a flea market, you don’t want it. Is the refrigerant listed on the EPA SNAP list for the specific application? If not, you don’t want it. Does it seem too good to be true? If so, you probably should avoid it like the plague.