The technology for natural refrigerant solutions across 99.9% of HVAC&R systems already exists and is mature enough for large-scale deployment, according to Armin Hafner, a Professor at Norwegian University of Science and Technology (NTNU).
Bottlenecks in widespread adoption include market acceptance, end-user awareness and a shortage of skilled engineers and technicians, Hafner told Jan Dusek, Co-Founder and COO of ATMOsphere, in an interview at the 17th IIR-Gustov Lorentzen Conference on Natural Refrigerants (GL 2026). ATMOsphere is the publisher of NaturalRefrigerants.com. Hafner also gave the keynote address at GL 2026, which was held August 23–26 in Hamilton, New Zealand.
“We don’t know the properties and all the effects of the new [synthetic] fluids,” Hafner said. “However, we know how to safely implement natural refrigerants – ammonia [R717], CO2 [R744], water [R718], hydrocarbons and air [R729].”
Hafner outlined the scope and impact of refrigerants. He shared examples of natural refrigerant technologies already in use and highlighted issues the industry needs to address.
Refrigeration accountability
The world’s over 5.4 billion operating refrigeration units account for 20% of global electricity demand and are responsible for 9% of global CO2 emissions, Hafner said. He added that scientific research indicates that 60% of global trifluoracetic acid (TFA) emissions come from refrigerants.
As a short-chained PFAS (per- and polyfluoroalkyl substance), TFA results from the atmospheric breakdown of synthetic refrigerants, notably HFO R1234yf (100% conversion) and HFC R134a (up to 20% conversion). In June 2026 the European Chemicals Agency (ECHA)’s Risk Assessment Committee (RAC) recommended classifying TFA as a reproductive toxicant.
Ready to scale
The mobile air-conditioning (MAC) sector accounts for the majority of R1234yf use. As an alternative, Hafner pointed to the one million electric vehicles using CO2 MAC heat pumps, as well as the development of CO2 and low-charge indirect propane (R290) systems for heating and cooling passenger vehicles, buses and trains.
For domestic hot water demands, CO2 heat pumps offer an “exceptional” solution, Hafner said. As an example, he cited Japan’s adoption of the technology, with over 10 million CO2 hot water heat pumps installed in the country since Eco-Cute introduced its first 6kW (1.7TR) unit in 2001. Along with domestic hot water, CO2 heat pump chillers offer simultaneous heating and cooling, making the units “well suited” for hotels, hospitals, schools, district energy and industrial sites.
Hafner also pointed to the widespread use of hydrocarbons in smaller refrigeration applications as evidence that natural refrigerants can already be deployed safely at scale. “We see tens of millions of [hydrocarbon] refrigerated bottle coolers,” Hafner told Dusek, arguing that R290 split air-conditioning systems should likewise be possible.
Progress in a single country
India is phasing down HFCs and has committed to achieving net-zero emissions by 2070. Hafner said both large stakeholders and smaller companies in India see natural refrigerants as an opportunity to compete in the global market.
As an example, a new food processing plant is using a locally manufactured CO2 heat pump chiller to preheat boiler feedwater. Hafner described the installation as a “first” for India, adding that the global end user intends to openly share the results after compiling a year of operational data.
For small fishing boats, India is developing a shipboard ice-making machine featuring a locally developed CO2 compressor in an open design, with the compressor and motor housed separately. “If they can make ice on board instead of taking it with them on the way out, they can maintain the quality of the catch even if the trip doesn’t go as planned,” Hafner said.
With assistance from the GIZ (the German Society for International Cooperation), Indian manufacturer Godrej & Boyce converted its split AC production from R22 to R290 in 2012. To cut costs and improve competitiveness, the company now manufactures its R290 compressors in India instead of importing the component, Hafner reported.
Expanding applications
In collaboration with the independent Norwegian research institute SINTEF, Hafner’s NTNU team is developing and testing HTHPs to decarbonize industrial processes, with a joint laboratory used to test systems and validate models. Moreover, many HTHPs are already operating in the field, according to Hafner. “By monitoring systems and sharing data, we can bring this technology forward as fast as possible,” he said.
In the commercial HVAC space, Hafner said R290 or CO2 heat pumps can now be incorporated into air-handling units (AHUs) to heat or cool supply air. He noted that R290 works well with an appropriate safety assessment and system design, while properly designed CO2 units can achieve the same SCOPs as systems using synthetics.
For R290 split AC units, Hafner remarked that innovative oil-free compressors could help drive market adoption. “If 20% of the refrigerant fluid is typically oil, an oil-free compressor gives you 20% more charge for cooling,” he said. He noted that component manufacturers such as German OEM ebm-papst are already manufacturing this technology.
Addressing bottlenecks
“The biggest problem in the next 5‒10 years for the industry is having enough engineers, installers and technicians,” Hafner told Dusek. Although manufacturers can streamline installation with factory-assembled units, someone still has to install it. Hafner suggested encouraging young people to join the industry and recruiting potential candidates from other sectors.
Making end users more aware of the environmental impacts of synthetics while being transparent about the potentially higher costs of sustainable options would create market demand for natural refrigerant solutions, Hafner said. He compared this approach to health warnings on cigarette packaging. “When you buy a box of cigarettes, it says, ‘Smoking kills,’” Hafner said. “We need something similar for TFA.”
Delaying restrictions on PFAS and TFA will also delay adoption of natural solutions already available commercially, according to Hafner. He believes end users will adopt natural refrigerants as a long-term investment, but only if they know that synthetic alternatives are a bad asset.
“Bans on TFA will come sooner or later,” Hafner told Dusek. “But the sector is ready to transition to natural refrigerants now. We need to implement what we know and not get more TFA in our environment than is necessary for us and future generations to deal with.”
“The sector is ready to transition to natural refrigerants now.”
Armin Hafner, a Professor at Norwegian University of Science and Technology
