Why R744 (CO2)?
Because Later Is Too Late
Regulations are tightening because synthetic refrigerants come with growing concerns—from health risks to environmental impacts. R744 stands apart as a safe, natural, and efficient refrigerant, offering businesses and communities a clear path to sustainable refrigeration and heating for many commercial, industrial, and district energy applications.
A Sensible, Future-Proof Refrigerant
R744 (refrigerant-grade carbon dioxide) chillers, heat pumps and refrigeration systems don’t come with the environmental and health risks associated with conventional systems that use synthetic refrigerants, natural gas, or all-electric heating.
As a refrigerant, R744 offers:
Zero ozone depletion potential
Ultra-low global warming potential
No flammability
No corrosiveness
No toxicity at low concentrations
No PFAS (“forever chemicals”) pollution
No risk of regulatory bans
Economical recharges
High thermal conductivity
Excellent flow and heat transfer performance
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Environmentally Responsible
R744 has zero ozone depletion potential and an ultra-low global warming potential (GWP) of just 1. In contrast, HFCs have GWP values hundreds or thousands of times higher—up to 12,000, making them among the most potent greenhouse gases in existence. Plus, unlike many HFCs and HFOs, R744 does not contribute to PFAS (“forever chemicals”) pollution of our environment, drinking water, and food supply.
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Future-Proof
When you choose R744, you avoid the potential of stranded assets caused by ever-stricter refrigerant regulations. Unlike synthetic F-gas refrigerants, R744 is not facing legal restrictions. (HFCs are being phased down due to their high GWP. HFOs, their lower-GWP synthetic replacements, are also at risk of being banned or phased down because of PFAS toxicity.)
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Versatile
With a wide working temperature range, R744 is suitable for a broad spectrum of mission-critical applications—from commercial building heating and cooling to industrial processes to district energy. Plus, R744 makes it possible to take advantage of heat recovery opportunities, which provides extra flexibility when designing solutions for maximum energy efficiency and sustainability.
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Space-Saving
Thanks to its high volumetric capacity and excellent flow and heat transfer performance, R744 allows for up to 4-5 times smaller system components versus comparable F-gas equipment. For example, pipe diameters, compressors, and heat exchangers can all be made much smaller. Plus, with its heat reclaim capabilities, R744 makes it possible to replace multiple pieces of stand-alone equipment (e.g. chillers and boilers) with a single, more compact heating and cooling system.
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Efficient & Cost-Effective
For many heating and cooling applications, R744 systems can provide a lower total cost of ownership versus F-gas systems. Thanks to its high thermodynamic performance, R744 is great for reducing annual energy consumption. And because it faces no restrictions and can be up to 12–20 times less expensive than increasingly scarce F-gas refrigerants, R744 helps protect you from rising refrigerant costs. In addition, R744 systems are generally built with higher-quality components, which can result in longer equipment life and lower lifetime maintenance costs.
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Proven
R744 isn’t new to the game. It’s been in use for more than a century. Over the last few decades, its use has expanded exponentially as organizations discover its performance and reliability. As of December 2023, more than 84,000 sites across Europe, Japan, and North America have R744 installations for large commercial and industrial applications. Thanks to ongoing technological advancements, R744 systems are even being used efficiently in warm climates.
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Safe
R744 is an ASHRAE A1 refrigerant, meaning it is considered safe, non-flammable, and non-toxic at low concentrations. Because it is chemically inert, R744 is also non-corrosive.
Lower your greenhouse gas footprint
20-year global warming potential (GWP) comparison based on IPCC AR6 (2021) values
Global warming potential (GWP) is a measure of how much a specific type of gas contributes to the warming of the planet over a given period of time, relative to carbon dioxide. CO2 has a GWP of 1 at all time scales. In contrast, the 20-year GWP of some of the most common hydrofluorocarbons (HFCs)—widely used synthetic refrigerants—can range from 323 to 12,000.
High-GWP fluorinated gases (F-gases) like HFCs are released into the atmosphere from leaks in refrigeration systems, the servicing of those systems, and the very process of manufacturing man-made refrigerants. For example, the refrigeration system of a typical supermarket leaks about 25% of its refrigerant charge each year, on average.
When used as a refrigerant, CO2 (R744) enables you to avoid the release of high-GWP emissions that have dramatically greater warming impacts on the climate.
With an R744 heat pump, you can also reduce or eliminate your need for all-electric heaters or natural gas boilers that have higher energy requirements and larger carbon footprints.
Reduce potential health threats posed by synthetic refrigerant emissions
Some newer synthetic refrigerants, such as hydrofluoroolefins (HFOs), are marketed as having low GWP values. For instance, HFO-1234yf has a 20-year GWP of 1 (the same as CO2). However, the production of HFOs results in significant greenhouse gas emissions. And when it comes to man-made refrigerants, GWP isn't the only major issue of concern.
In the atmosphere, HFOs can degrade to trifluoroacetic acid (TFA) due to photooxidation caused by sunlight. HFCs can also break down, partially, into TFA. That TFA then falls to the surface through precipitation and accumulates in water and soil, including sources of drinking water. TFA doesn't easily break down in the environment and may be impossible to remove once there.
We don't know all the long-term effects of TFA on ecosystems and human health at this time. However, TFA meets the OECD's definition of perfluoroalkyl and polyfluoroalkyl substances (PFASs), which are a group of human-made "forever chemicals" it has designated as posing concerns for the environment and human health (including cancer risks).
Canada's State of PFAS Report uses the OECD definition of PFAS, which could lead to strict regulations or bans on the substances, following the path of other nations as well as some U.S. states. As Canadian Environment Minister Steven Guilbeault said, "Only diamonds should be forever, not human-made substances that are polluting our environment."
So the use of HFOs and "low-GWP" HFCs as replacement refrigerants is a major gamble. HFOs and TFA threaten our future.
Should we trust the reassurances of the F-gas industry? It's the same industry responsible for past denials about ozone-depleting chlorofluorocarbons and hydrochlorofluorocarbons (CFCs and HCFCs) as well as toxic PFAS chemicals.
In the U.S., the EPA has proposed regulations for PFAS in drinking water. And European countries are proposing extensive PFAS bans.
Let's not trade one crisis for another.
R744 and other natural refrigerants allow us to safely bypass these risks altogether. No gambling required.
Avoid being strangled by increasing regulations
Like CFCs and HCFCs before them, many HFCs are being phased down around the world because of their environmental harm. Several high-GWP HFCs will soon be banned outright in the United States and other countries for most cooling applications. This is how it goes with synthetic refrigerants. See:
CFCs and HCFCs are bad solutions because they deplete the earth's ozone layer. HFCs are bad solutions because they are "super-pollutant" greenhouse gases, hundreds or thousands of times more powerful than CO2 at trapping heat. How long until HFOs are concluded to be bad solutions because of the high greenhouse gas emissions from their production and their potential toxicity to the environment and/or human health?
Further HFC bans are likely. And future HFO bans are a distinct possibility. That would be the end of the road for F-gases. In fact, manufacturers of HFCs and HFOs may be causing ozone-depleting CFC emissions as unintended byproducts. So further bans could come sooner than anyone previously imagined.
Companies and communities have opportunities right now to avert future problems by choosing natural refrigerant systems. The alternative could mean having to replace costly F-gas systems prematurely or risk crippling fines or shutdowns.
Simplify and reduce your operating costs
As the phase-down of F-gases progresses, the cost of recharging a system with synthetic refrigerants is rising exponentially. Even newer synthetics—like HFOs that aren't yet banned—tend to be much more expensive than R744 or other natural refrigerants. With HFC bans and phase-downs already taking hold, companies and communities should expect the prices of synthetic refrigerants to increase with greater frequency.
R744 heat pump systems provide the flexibility to combine cooling and heating technologies in a way that saves space and maximizes efficiencies. You can replace multiple pieces of stand-alone equipment—like conventional chillers, boilers, and heaters—with a single R744 heat pump. Using the cooling and heating production of one R744 system empowers you to achieve major cost savings (in both energy and refrigerant recharges).
R744 systems help protect you from rising energy and refrigerant costs.