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A2L Refrigerant Standards and Regulations

The regulations regarding A2L refrigerant are found in a tapestry of Standards, Codes, and Rulings. I like to research using original documentation whenever possible. Not that I don’t trust the folks doing webinars, blogs, and videos, but when answering questions about new technology I want to be able to point to authoritative documents. So, I look for the actual standards, guidelines, and codes. I found it a bit confusing because there are so many agencies publishing many standards and regulations regarding A2L refrigerant. Furthermore, these standards often refer to each other. I have listed below some of the more important documents you should study if you like to do your own research.

ICC International Mechanical Code 2024, IAPMO Uniform Mechanical Code 2024
These completed but yet unpublished codes allow the use of A2L refrigerants in traditional HVAC systems and specify conditions for use of A2L refrigerant. They refer to AHRI Standards 15 and 34 2019 and UL 60335-2-40, 3rd edition.

Amendments to ICC International Mechanical Code 2021, IAPMO Uniform Mechanical Code 2021
Some states have passed amendments to their existing 2021 codes to allow the use of A2L refrigerants in traditional HVAC systems. Typically these amendments accomplish this by referring to AHRI Standards 15/34 2019 and UL Standard 60335-2-40, 3rd edition.

UL 60335-2-40, 3rd edition
This is the latest standard from UL for HVAC systems. It is similar to the international IEC standard with the same name and number. The provisions in it have already been in place in many other places around the world; including, Europe, Japan, and Australia. It spells out in detail how A2L refrigerant may be safely applied. It refers to ASHRAE Standards 15/34 2019.

ASHRAE Standard 15 – 2019 Safety Standard for Refrigeration Systems describes how refrigeration systems may be safely installed and operated. The 2019 edition includes specific conditions for A2L refrigeration systems.

ASHRAE Standard 34 – 2019 Designation and Classification of Refrigerants lists refrigerant safety ratings and important safety data for a long list of refrigerants, including several A2L refrigerants. Data listed in Standard 34 is used to determine specific system requirements detailed in Standard 15. Taken together, Standards 15 and 34 provide very clear guidance for application of A2L refrigerant.

ASHRAE Standard 15.2 – 2022 Safety Standard for Refrigeration Systems in Residential Applications is the low-rise residential companion to ASHRAE Standard 15. Standard 15 has historically primarily been applied to larger commercial buildings, not low-rise residential homes. Standard 15.2 describes in detail what must happen to safely use A2L refrigerant in a residential application.

EPA Final SNAP Ruling 23, April 2021
This ruling specifically allows the use of A2L refrigerants R-32, R-452B, R-454A, R-454B, R-454C, and R-457A in new residential and light commercial air conditioners and heat pumps. The rule incorporates UL 60335-2-40, 3rd edition by reference.

EPA AIM Act Final Ruling, Sept 2021
This ruling establishes the HFC allocations for the phasedown of HFC refrigerants under the AIM Act. One unexpected significant component of this ruling is a ban on disposable refrigerant cylinders beginning in 2025.

AHRI Guideline M 2020, Unique Fittings and Service Ports for Flammable Refrigerant Use specifies that service connections for systems with A2L refrigerant should be exactly the same as those used on systems with A1 refrigerant. The connection on A2L refrigerant cylinders is described as a CGA 164 connection. The CGA 164 connection is described in the CGA Standard V-1 2019 as a 1/4 inch flare with left hand threads.

CGA Standard V-1 2019 Standard for Compressed Gas Cylinder Valve Outlet and Inlet Connections introduces the CGA 164 connection. It is designed specifically for A2L refrigerant cylinders. The standard describes the CGA 14 connection as a 1/4 inch flare with left hand threads. While the CGA 164 connection is first introduced in the 2019 edition, the latest edition of the CGA V-1standard is now 2021.

UL Standard 207 Standard for Safety Refrigerant-Containing Components and Accessories, Nonelectrical covers nonelectrical, refrigerant-containing components and accessories in accordance with ASHRAE Standard 15. This standard is specifically referenced by ASHRAE Standard 15.2 when describing fittings, valves, and mechanical joints.

Taking AIM at HFCs

The American Innovation and Manufacturing Act of 2020, or AIM was passed as part of the most recent Covid 19 relief bill. In truth, that bill was really a collection of different pieces of legislation, including the AIM Act. Although you probably would not know it from the title, the AIM Act is about phasing down HFCs. We are kind of late to the HFC phasedown party. Europe has already begun and made significant progress toward reducing HFCs. For American air conditioning and refrigeration equipment manufacturers, supporting HFC reduction is about business because they market products to a global customer base. Although the law has now been passed, the details of exactly how this will affect us are yet to be determined and released. The law gives the EPA 270 days from the date it is signed into law (December 27) to pass a final ruling. That will have all the particulars. However, there are some important things we can learn from reading the law itself.

DOWN NOT OUT

This is a phasedown, not a phase out. Some HFCs will still be available for a long time. The timeline is not particularly aggressive, as you can see from the table below. This does not necessarily mean your favorite HFC will still be available at the levels in the table, the table is an overall HFC reduction. The nitty gritty details will be worked out in the Final Ruling to come.

Date% of Production Baseline% of Consumption Baseline
2020 – 202390%90%
2024 – 202860%60%
2029 – 203330%30%
2034 – 203520%20%
2036 –15%15%

What Refrigerants are Covered?

The law lists several specific HFCs, many of which I have never heard of. It actually does not list 410A, or any other 400 series refrigerants because it is regulating the chemical compounds of which they are composed.  It does list the two main components of 410A: R32 and R125. It also lists popular HFC refrigerant R134a. The table below shows the HFC compounds that are affected by the law.

HFCs Regulated by AIM Act
Chemical Name         Common NameExchange Value
CHF2CHF2 HFC–1341100
CH2FCF3 HFC–134a1430
CH2FCHF2 HFC–143353
CHF2CH2CF3 HFC–245fa1030
CF3CH2CF2CH3 HFC–365mfc794
CF3CHFCF3 HFC–227ea3220
CH2FCF2CF3 HFC–236cb1340
CHF2CHFCF3 HFC–236ea1370
CF3CH2CF3 HFC–236fa9810
CH2FCF2CHF2 HFC–245ca693
CF3CHFCHFCF2CF3 HFC–43–10mee1640
CH2F2 HFC–32675
CHF2CF3 HFC–1253500
CH3CF3 HFC–143a4470
CH3F HFC–4192
CH2FCH2F HFC–15253
CH3CHF2 HFC–152a124
CHF3 HFC–2314800

WHERE CAN I READ MORE?

Here is a link to the text of the AIM Act. If you are like me, you might find that the legal language in laws can be a bit obtuse. AHRI has put out a helpful overview of the law in more easily understood terms.

AHRI AIM Act Explanation

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