New Low GWP Non-Flammable R410A Replacement

This will be a short post because I don't know a lot of details yet. Honeywell is developing a new three part zeotropic refrigerant that can replace R410A. It has a relatively low GWP of 733 compared to 2088 for 410A, and most significantly, is non-flammable. Honeywell's trade name for it is Solstice N41, the ASHRAE number is R466A. It reportedly contains the same two chemicals as in R410A (R32 and R125). A third is added - trifluoroiodomethane (CF3I). This third component is currently used a a fire retardant. It also helps reduce the GWP of the mixture. The new refrigerant is not claimed to be a "drop-in" for R410A, but required design modifications are said to be minimal. The refrigerant is currently undergoing ASHRAE testing, but has received a preliminary A1 rating.  I have now told you all I know, and it did not take very long. Here are links to two articles about this new refrigerant.
https://www.coolingpost.com/world-news/secret-of-honeywells-new-refrigerant/
https://www.coolingpost.com/world-news/honeywell-announces-r410a-breakthrough/
 

Court Rules Against EPA SNAP Ruling

Two refrigerant manufacturers, Mexichem and Arkema, have successfully sued the EPA over their decision to start phasing out HFC refrigerants because of their global warming effect. The gist of the argument is that the law which established the EPA’s right to regulate refrigerants is specifically about ozone depletion, not global warming. The EPA’s legal right to regulate replacement refrigerants is limited to their effect on ozone depletion. The court ordered the EPA to redo their ruling with this in mind. Below are a couple of direct quotes from the ruling.

“The fundamental problem for EPA is that HFCs are not ozone-depleting substances, as all parties agree. Because HFCs are not ozone-depleting substances, Section 612 would not seem to grant EPA authority to require replacement of HFCs. Indeed, before 2015, EPA itself maintained that Section 612 did not grant authority to require replacement of nonozone-depleting substances such as HFCs.”

“EPA’s novel reading of Section 612 is inconsistent with the statute as written. Section 612 does not require (or give EPA authority to require) manufacturers to replace non-ozone depleting substances such as HFCs. We therefore vacate the 2015 Rule to the extent it requires manufacturers to replace HFCs, and we remand to EPA for further proceedings consistent with this opinion.”

The EPA still has to do their rewrite, and of course it is possible that they might choose to appeal to the supreme court. But for now, the HFC phase down has been phased out.

You can download the ruling and read it for yourself here:

https://www.cadc.uscourts.gov/internet/opinions.nsf/3EDC3D4817D618CF8525817600508EF4/$file/15-1328-1687707.pdf

Below are two links to other articles about this ruling.

http://r744.com/articles/7787/u_s_court_rules_hfcs_cannot_be_limited_by_current_epa_rules?utm_source=mailchimp&utm_medium=email&utm_campaign=Bi-weekly+Newsletter

http://cen.acs.org/articles/95/web/2017/08/Court-strikes-down-US-restrictions-on-HFCs.html

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

Refrigerant Don'ts

With summer now upon us and the price of R22 skyrocketing there are many questions regarding replacement refrigerants. This discussion could fill a book, so I am going to restrict this post to a list of don'ts. The intent is to help people avoid issues that can be caused by improper application of 400 series R22 replacements.

Do NOT use a flammable replacement refrigerant in ANY system originally designed for R22. There are some hydrocarbon (propane) based replacement refrigerants sold online. They are NOT EPA approved and represent an explosive hazard when charged into a system that was not designed for flammable refrigerant.

Do NOT add ANY replacement refrigerant on top of an existing R22 charge. This is an EPA violation. You are essentially creating a “new” refrigerant which has not been tested or approved. There are NO replacement refrigerants which are legal to add in on top of an existing R22 charge. You must first remove ALL of the R22 when doing a conversion.

Do NOT use ANY 400 series refrigerant in a flooded system. Even refrigerants which are advertised to work in systems with mineral oil will still separate in the flooded portions of the system because they are not truly miscible. There is a difference between miscibility and solubility, but that is the subject for another whole article.

Do NOT use ANY replacement refrigerants in ANY system using an electronic expansion valve. This would primarily be older R22 minisplits, multisplits, and VRF systems. Trane hyperion heat pumps can sometimes have an R22 charge. In that specific case, the indoor air handler is designed for both R22 or R410A, so switching to R410A and changing the refrigerant dip switch solves that problem for the indoor air handler. Unfortunately, you will still have to replace the outdoor unit with one designed for R410A.

Do NOT use ANY 400 series replacement refrigerant in systems which were originally designed for R22 and have Trane 3D Scroll compressors. The lubrication system that specific compressor design uses does not work well with HFC refrigerants, including ones advertised as being compatible with mineral oil.

This all come down to one main strategy for replacing R22 in most older systems: it is generally best to replace the whole system. Not only does this avoid application problems, it usually provides a significant efficiency upgrade as well.

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

R-22 Conversion - What to Avoid

After reading a lot of technical literature, attending several talks and seminars on R-22 conversion I have developed the following cautions on R-22 conversion.

First and foremost – if you convert a system from R-22 to ANY replacement refrigerant, you are conducting a field experiment on the customer’s equipment using their money. Make sure the customer understands that they are paying for an experiment which may or may not end successfully. I think I would get that in writing.

Since all the replacement refrigerants are zeotropes, they should not be used in flooded systems because they will fractionate in the evaporator.

Since all the replacement refrigerants are immiscible with mineral oil, they should not be used in systems with large receivers (without changing the oil to POE) because the mineral oil will separate and float on top of the refrigerant in the receiver.

Some of the replacement refrigerants have trace amounts of hydrocarbons or POE to help prevent oil logging in the coils and lines. This works well in many systems, but it does not help in the receiver where there is not much refrigerant movement.

DuPont says that the churning in accumulators discourages separation in the accumulator. However, they also say that you may need to add 10% POE if you have oil return problems. 

I am nervous about heat pump accumulators – especially in cold weather when a large amount of the charge is just sitting in the accumulator.

You should NOT weigh in the same amount of replacement refrigerant as R-22 because all the replacement refrigerants are less dense than R-22. A general rule is somewhere around 75-80%.

You should NOT just try to match the pressures you are used to seeing with R-22. A better indicator would be to measure the system subcooling and superheat and shoot for “reasonable” numbers.

You should replace all O-rings and Schrader valve cores before putting in the new refrigerant. O-rings can shrink when exposed to the new refrigerant creating a leak where none previously existed.

You should NOT just add the new refrigerant on top of the R-22. If you do that, you are creating your own special blend which is not EPA SNAP approved.

Just because a refrigerant matches the pressures of R-22 does not mean it will match the mass flow rate. If the mass flow rate is too different from R-22 the metering device won’t work correctly.

Make sure any refrigerant you use is EPA SNAP approved for the application. Any reputable refrigerant will have an ASHRAE refrigerant number and safety rating – not just a trade name or number.

One way to be sure what you are using is safe is to only buy refrigerant from recognizable manufacturers at normal supply houses, not online.

Under NO CIRCUMSTANCES should you use any of the “Organic” replacement refrigerants available on the internet. The “organic” components are propane and butane. They don’t have trace amounts of hydrocarbons, they are ALL hydrocarbon. These refrigerants are NOT EPA approved and they are NOT safe to use in a system which was not designed for flammable refrigerant.

If the customer has already purchased some “organic” refrigerant and tried charging their system, I would not work on the system. It is an accident waiting to happen.

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.