I know a lot more about the National Electrical Code and electrical installations than I do about air conditioning. However, when I attended the 2026 NEC Comment meetings in Torrance, Calif., during the third week of October 2024, I heard rumblings about a new refrigerant and redesign for air conditioning units.

When I came home, I started doing research on the new requirements. My next-door neighbor works for an air conditioning and heating contractor in Scottsdale, Ariz. He was able to answer some of my questions on the redesigned units and the new refrigerant that were mandated as of Jan. 1, 2025.

I then called my grandson, Steven, who is one of the best air conditioning unit technicians and troubleshooters, and he gave me more valuable information. I then accessed as much on this subject as I could find on the internet. 

In this article, I will attempt to cover this subject and more about air conditioning and heating units as well as new information about the new refrigerant. These changes may involve new units installed after Jan. 1, 2025; Article 440 of the NEC may also be affected.

Old versus new

A refrigerant is a fluid used in a refrigeration, air conditioning or heat pump system that changes from a liquid to a gas and absorbs heat before cycling back into a liquid. In the 1970s–’90s, R-22 refrigerant (often called “freon”) was used in air conditioning and refrigerating systems.

Studies in the 1970s indicated that R-22 released into the air was adversely affecting the atmosphere’s ozone layer. The ozone-depleting properties of R-22 required gradually phasing it out. The Environmental Protection Agency has banned R-22 freon, stopped its use in the United States in 2010, and banned any new air conditioning systems using R-22 from being manufactured or imported. If you have an existing air conditioning unit with R-22, as long as there isn’t a leak, there is nothing to worry about, though replacement R-22 has become very expensive.

Two new refrigerants were introduced that were zero-ozone-depletion substitutes: R-410A is the most commonly used, and R-422D is an alternative (also called freon MO99) used to retrofit R-22-based low- and medium-temperature air conditioning and refrigeration systems. Neither of these refrigerants are ignitable, with R-410A rated at a classification of A1 and no flame propagation; however, the oil in the refrigerant lines is ignitable, so care must be used when soldering these refrigerant lines.

Starting in 2025, the new refrigerant is R-454B. It is slightly more flammable, but as a classification of A2L, can only ignite under very specific conditions and is only slightly more likely to catch fire than the A1 refrigerant. New air conditioning technicians must undergo special training on how to safely handle this new refrigerant. R-454B has more than 75% lower global warming potential than R-410A refrigerant, based on testing.

New air conditioning units using R-454B refrigerant will be about 2%–3% more energy efficient than R-410A refrigerant (depending on the specific system design and operating conditions), so it won’t negatively affect residential energy bills. However, the new units will be between 15% and 20% more costly to install, since the change requires a totally redesigned system.

Why should electricians care?

The question I have is, will it affect the electrical nameplate power at the air conditioning unit? Based on all of the aforementioned information, that is what interests me most as an electrician. From what I understand of the new units, the refrigerant line will have a higher pressure than the older R-410A lines, with possible higher compressor head pressure, depending on the outside ambient temperature for the compressor. 

Here in the Phoenix area, the hotter the temperature is outside, the higher the head pressure for the compressor, resulting in higher startup current for the compressor motors. This will certainly depend on the design of the new air conditioning units.

Some units have a higher seasonal energy­-efficiency ratio 2 (SEER2) rating, which is the ratio of the cooling output of an air conditioning unit over a typical cooling season divided by the energy it uses in watt-hours. 

The higher the unit’s SEER2, the less its overall energy consumption. Older units were in the SEER 10 to 14, with newer, more expensive units being in the high 18 to 21.5 values. An 18 SEER2 unit is 26% more efficient than a 14.3 SEER2 unit at 6% rated efficiency.

As these new air conditioning units are installed, check the electrical specifications before deciding the size of the branch circuits, conductors and disconnecting means using the Article 440 requirements for air conditioning systems.

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