Variable Refrigerant Flow (VRF) systems are a popular HVAC system, providing efficient heating and cooling with great reliability. However, these systems are going through a major technology transition due to the phase-out of the refrigerant they use, R-410A. As of January 2026, it is illegal to manufacture or import new R-410A VRF equipment in the United States.
What Is VRF?
A VRF system includes a single outdoor unit connected to multiple indoor units by a network of field installed refrigerant pipe. Manufacturer controls coordinate these units to meet shifting heating and cooling needs. VRF systems are especially popular in small- to-medium-sized medical office, commercial office, and higher education buildings.
Why the Change Is Happening
R-410A is being phased out to reduce the climate impact of inevitable refrigerant leaks. R410a has a Global Warming Potential (GWP) of 2,088 (2,088 times more potent than CO2). All VRF manufacturers are shifting to refrigerant R-32, which has a GWP of 675: much better, but still significant given VRF systems contain two to ten times the quantity of refrigerant of other HVAC systems.
This phase-out is the latest in Federal safety and environmental requirements dating back to the 1990’s. Like previous phase-outs of R-12 (Freon) and R-22, the EPA coordinated this phase-out with industry as better alternatives became viable. These regulations have broad bi-partisan political support in the US and are consistent with regulations in other nations, including the EU, UK, Japan, Canada, and Australia.
What’s Different this Time?
R‑32 and similar lower GWP refrigerants are mildly flammable, and didn’t fit North American safety regulations, which were either excessively strict and impractical for VRF, or not safe enough. A new ‘A2L’ safety classification was created, with new safety standards. In 2024, it looked like the regulations might be too onerous for VRF systems to continue, but final refinements in 2025 struck a practical balance.
New common-sense life‑safety components, including refrigerant sensors, isolation valves, controls, and alarms are now integrated standard in VRF equipment.
Engineers responsible for the application of R-32 VRF systems have numerous small differences with calculations and layout. We find there are more and different details to resolve, but no “game changers”.
For owners, there are several practical implications:
- Equipment costs are higher to accommodate the new safety features. On the first R-32 VRF system we’ve designed, the equipment cost premium was 11%.
- We expect nuisance issues with the new safety features in the short term. The development timeline for equipment has been rushed, and unlike previous developments with VRF, new safety components are coming to North America without decades of use abroad.
- Commissioning is even more critical. Proper up-front verification of safety systems, including controls and alarms should help minimize operational disruptions and costs.
The Takeaway
VRF systems are still a great option. With the new refrigerant they are now a safer for occupants and much safer for the climate.
By: David Okada, Senior Project Engineer