When the discussion turns toward building for the future, a key initiative is the HVAC industry converting to refrigerants with lower global warming potential, known as GWP. Consulting-Specifying Engineer (CSE) sat down with Tate Byers, senior product manager for the Lennox Rooftop Series at Lennox Commercial with 10 years of experience in HVAC product development and product management, to dive into some frequently asked questions about the 2025 refrigerant transition, to help everyone understand what to expect and how to stay ahead of the curve.
CSE: Help us understand the 2025 transition to low-GWP refrigerants across North America and beyond. To start with, what is changing in our industry?
Byers: There’s a lot of change happening. The U.S. Environmental Protection Agency (EPA) is taking a phased approach to cut out the use of HFCs, which have a higher global warming potential. As part of this transition, the EPA set an end date for production of HVAC equipment that utilizes refrigerants with a GWP higher than 700. So that would be the R-410A that everyone is used to today. Beginning January 1, 2025, any HVAC system, excluding VRF, manufactured in the United States has to use a lower GWP refrigerant that is less than 700. Most manufacturers went with R-454B, but one or two have used R-32 to get below that threshold set by the EPA.
What’s Lennox’s overall strategy when transitioning to these new refrigerants?
Our engineering focus, and our strategy as a business, is to make the transition safe, simple and effective. Our No. 1 priority is safety, and after that we want to make it as simple as possible for the technicians and our customers. We think that’s going to lead to a seamless transition throughout the industry.
Regarding safety, how flammable are A2L refrigerants?
A2L refrigerants are a new classification for lower flammability. They can ignite under certain circumstances, but safety standards require products to be designed to greatly reduce the probability of these conditions occurring. When we prepared for the transition with our product designs, we implemented new safety systems that reduce the ignition chance of the refrigerant.
What happens when the refrigerant detection system detects a leak?
As soon as a leak is detected, regardless of the unit’s current state — whether it’s cooling, heating or just idle — the blower will either turn on or remain on and servicing demands like heating and cooling are no longer allowed. At the same time, in the Lennox equipment, an alarm is triggered to alert that a leak has been detected.
When it comes to the industry standard, what you’ll see is that once a refrigerant leak is detected, the safest thing to do is to dissipate that refrigerant below the lower flammability limit.
How are installations different from R-454B to R-410A units?
From an installation standpoint, there’s not a lot of meaningful change between the installation of the two units. When it comes to packaged rooftops, everything is factory installed and the unit comes ready to be installed just as if it were an R-410A unit.
With split systems, there are some changes in the way that the refrigerant piping is installed throughout a building. Your local code authority should be consulted for specific requirements for refrigerant piping.
Speaking of rooftop units known as RTUs, with low GWP refrigerants. Can they be used on the same buildings as R-410A equipment?
Yes, when it comes to the same building, absolutely they can be installed. Across the industry today, we have a mix of refrigerants on top of rooftops. Since they’re not intermingled in any way, there’s no restrictions on whether a building can have the same or different types of refrigerants on it. It’s pretty simple from that standpoint when it comes to the installation side.
What are the Federal sell-through standards?
It varies by product. There will be a three-year sell-through period for residential and light commercial packaged rooftop units. There’s also a one-year sell-through period for ducted residential or commercial split systems. That’s a new system installed with an indoor and outdoor unit together. If you’re just replacing the outdoor unit, those have an indefinite sell-through period when sold individually as a repair part. There are some nuances, but for the most part packaged equipment gets a three-year sell-through period, and new installation split systems have one year.
Any final comments?
We’re focused on educating the industry. This is a big change for everybody, from engineers to contractors to technicians. Anything we can do to be of service, we’re happy to do it.
To learn more about the Low GWP transition, visit our Low GWP page, lennox.com/commercial/resources/low-gwp, where you can find more information on navigating the transition.
