Alright, let’s cut to the chase and talk about refrigerants found in nature. If you’ve been sweating out those increasing energy bills; or fretting about your company’s carbon footprint; or even just fet a queasy twinge at the words “HFC phase-down,” then you have indeed come to the right place. We’re delving into the cooling tech that’s not only kinder on the planet, but could actually save you some money in the long term.

So, what are we even talking about? Natural refrigerants are those that you also find out in nature, for instance, ammonia, carbon dioxide or hydrocarbons such as propane and isobutane. Now, don’t get it twisted: They’re still made on an industrial scale, just like other refrigerants. But the thing here is their origin story: they are naturally occurring compounds, not synthetic chemicals invented in a lab. The big deal? They’re reinventing the refrigeration and cooling world and bringing to the table a pretty fantastic solution to those chemical dudes CFCs, HCFCs and HFCs. They’re gaining huge traction because they have little to no baggage when it comes to global warming potential (GWP) and ozone depletion potential (ODP). That’s a game-changer.

Reasons to Look at Natural Refrigerants: The Big Wins

You may be wondering, “So what? A refrigerant’s a refrigerant.” But believe you me, there’s a stack of reasons why these naturally rogue bad boys are fast-becoming The One. It is about sustainability, not only of the planet but of your bottom line.

Here’s a rundown of why they’re such a future-proof choice:

• Climate-Respectful MVPs: This is enormous. When we’re talking about GWP, we’re talking amounts of global warming — with CO2 being the reference point (GWP = 1). Because when are they released into the atmosphere, synthetic refrigerants—especially high-GWP HFCs like R134a (GWP 1430) and R404A (GWP 3922)—are akin to throwing a match on a gas leak. Natural refrigerants? They have GWP value from 0 to about 5.5. Consider this: Ammonia has a GWP of 0, while CO2 is a neat 1. And for ozone depletion potential (ODP) — the damage to the ozone layer — it is a perfect zero for natural refrigerants. And that means they’re not only better; they’re light-years better for the environment, directly contributing to cutting greenhouse gas emissions.
• The Cost-Cutting Cheat Code: Yes, I know, you hear “eco-friendly” and your wallet concaves. And here’s the kicker: natural refrigerants are cheap to make and they are available for the long-term. And while some systems might look more complicated or costly to build in the first place, when you zoom out to account for total lifetime costs — including installation, operation and disposal — systems powered by natural refrigerants tend to have the lowest lifetime costs. That, folks, is investment security.
• Energy Efficiency That Bends: It’s all about making every watt count, right? And as natural refrigerants, ammonia and some hydrocarbons (like R290) are discomfiting only if we ignore the fact that they and a few other candidates are champions of energy efficiency. True Manufacturing, for example, cites R290‘s excellent thermodynamic properties that enable it to to absorb a greater amount of heat more quickly, which results in a faster pull-down time and lower energy consumption. We’re talking about up to 48 percent less energy consumption for some units. Not only is that good for the planet, it’s straight at your power bill.
• How To Future-Proof Your Operations: Refrigerant regulations continue to tighten around the world. As for the small carbon footprint, natural refrigerants are pretty much impervious to future phase-outs. You make the switch now, and you’re good to go, skipping out on the potentially expensive forced upgrades in the future.

A Short History Lesson: From Natural to Not-So-Natural and Back Again

Picture refrigeration without the exotic chemicals. What did they use? You guessed it: natural refrigerants. Ammonia was a heavyweight, used in absorption refrigeration systems as far back as the 1800s and even in compression machines by 1876. Carbon dioxide also appeared around the early 1900s, and its use was patented in 1850 in the U.K. These were the OGs — all-natural, easy to find.

Then came the 1930s — and everything changed. Enter CFCs (chlorofluorocarbons). These artificial chemicals were a godsend: They were good at shuffling heat around, they were stable, and, most important, they were nontoxic and nonflammable. They have quickly been substituting ammonia and CO2 in many applications. For a time, CO2 all but disappeared, although ammonia retained its toehold in large industrial applications.

Fast forward to the 1980s, when the inconvenient truth struck home: Those wonder chemicals — CFCs — were punching holes in our ozone layer. Not ideal. The world responded with the Montreal Protocol in 1987, which ultimately phased out CFCs by 2010. Next came HCFCs (hydrochlorofluorocarbons), which were a little better but still had some ozone-wrecking chlorine, with a phaseout scheduled for 2020/2030.

Frosty, my, but things were ringing as that synthetic train rolled on to the HFC (hydrofluoro)carbons. They had no chlorine, so no ozone damage, right? Problem solved? Not quite. It turns out: HFCs are dangerous and powerful global-warming gasses with extremely high GWP, creating thousands and thousands of times as much heat-trapping power as CO2. So, in 2016, the Kigali Amendment asked for an 80% reduction of HFCs over 30 years. And here in the US, the AIM Act that was signed into law late last year also instructs US EPA to phase down US HFC production and consumption by 85 percent by 2036, driving cleaner different tech and improved refrigerant management.

This entire sojourn — from natural to synthesized and back again to natural — is fueled by environmental urgency and advancing tech. It’s the reason that the industry around natural refrigerants is expected to grow 8.5% over the next four years, to become a $2.88 billion industry by 2027. The cast has been set for the future: natural refrigerants are back, and they are back to stay.

The A-Team of Natural Refrigerants: Who’s Who and What They Do

Let’s meet the main players. Each comes with its own personality, strengths and quirks.

Ammonia (NH3, R-717)

• The Workhorse: There’s a reason why ammonia has been in the refrigeration game since 1872—it’s highly efficient and has great thermodynamic properties. Oh, yeah: And it’s lighter than air, which is a pretty cool trick as well.
• Eco Report Card: GWP 0, ODP 0. It has literally no effect on global warming or when it comes to leaks ozone depletion. That’s a mic drop moment.
• Safety Check: Fine, here’s the real talk. Ammonia is toxic (B2L by ASHRAE), but don’t worry. The good news? You can smell it at extremely low concentrations (as low as 5 ppm), well below the concentration that will kill you (above 300 ppm). So there’s a leak, you’ll know. Fast. Flammability is also “reduced flammability” (16–28% concentration) and you would smell it before it got anywhere near being a problem. The key engineering consideration is that it’s not compatible with copper and copper alloys. This involves special system designs, but it’s a mature technology.
• Where It Shines: Ammonia reigns supreme in commercial refrigeration. “We’re talking chemical plants, monster cooling requirements, pharmaceutical facilities, big food and beverage processing — the list really goes on and includes large HVAC chillers, process cooling, district cooling and heat pumps,” he says. And it’s popping up in supermarkets and convenience stores. In cascade refrigeration systems it frequently travels in tandem with CO2 to reach super-low temperatures.

Carbon Dioxide (CO2, R-744)

• The Comeback Kid: CO2 was in use in the 1800s but was dropped in the wake of CFCs. Now, it is experiencing a huge resurgence. It is not flammable, and it is non-toxic.
• Eco Report Card: GWP 1, ODP 0. It’s the standard for GWP, so you know it doesn’t get any better.
• Safety Check: The EPA classed it as A1 (the lowest toxicity/hazard). The heaviest part of the tiny unit is — get this! — the ground plane, which you install to your exterior mast or metal water pipe to set up a grounded system. One thing to note: it’s heavier than air, so if it leaks in an enclosed space, the gas can crowd out the oxygen, meaning low-mounted alarms might be necessary.
• The Pressure Play: That’s CO2 that can’t stand the pressure. Instead, it condenses — but at much higher operating pressures, up to 200 atmospheres, to condense. That means specialized, hardened equipment, and in general you can’t just retrofit old systems. But this “problem” is also a superpower: higher pressures mean higher gas densities and more refrigerating effect for you. This makes it a killer for cooling densely packed heat loads—say, server rooms, where the IceBear performs terrifically in cold temperatures (-30 to -50 °C). You will see a lot in, commercial refrigeration, maybe automotive a/c, and many times in transcritical and cascade system.

Hydrocarbons (HCs – e.g., Propane R-290, Isobutane R-600a)

• The Workhorse of Options: Hydrocarbons are highly versatile with low GWP and superior thermal efficiency—up to 50% more efficient than some synthetic options. They occur naturally in oil and gas.
• Eco Rating: ODP 0, and extremely low GWP (Propane R-290 GWP=3).
• Safety Check: Now, let’s face it, hydrocarbons are flammable. ASHRAE classifies them as A3: low toxicity levels but very flammable. Since colorless and odorless, you will need strict safety requirements: lower charge size, good venting and system design so that ignition sources do not exist. But there’s a catch: Companies like True Manufacturing have figured out how to use them safely and effectively in commercial units.
• Where They Shine: Domestic refrigerators/freezers, portable air conditioners, and stand-alone commercial refrigeration units (beverage and ice cream machines). They’re also found in centralized indirect systems serving supermarkets, transport refrigeration and chillers. Only hydrocarbon refrigerants are used in all True Manufacture units, proving their dedication to sustainability.

Other Naturals: Water and Air

• Water (R-718): Cheap, non-toxic, non-flammable, GWP 0, ODP 0. The main challenge? It’s high specific volume at low temperature, and super low pressures required, makes it a difficult gas for vapor compression systems. Water used at higher temperatures is (so far primarily) confined to lithium-bromide absorption chillers, but can also include heat pump systems and other applications.
• Air: Free, non-toxic, and no environmental impact. Applied to air cycle air conditioning systems (reverse Brayton or Joule cycle). The ultra-efficient inverter systems are also becoming better as modern compressors and HX are coming to market.
• Noble Gases and Others: Noble gases (including liquid helium) are not used much beyond super-cool lab experiments. There are other compounds, such as diethyl ether or methyl formate, but they are less popular commercially because of flammability or handling issues.

Here’s are a few common refrigerants in terms of their GWP and ODP, to give you a look at why natural options are so exciting:

The Obstacles: Negotiating the Difficulties of Natural Refrigerants

No answer is perfect, though, and natural refrigerants present their own challenges. But here’s the good news: these are not show stoppers, they’re rather just design considerations that sharp engineers are now addressing head on.

• Flammability: This is the major one for hydrocarbons, and a minor one for ammonia. With hydrocarbons, you have to have robust safety designs — like charging in limited size charges and good ventilation to keep concentrations below flammable limits. It’s smart engineering?not avoidance altogether.
• Toxicity: Ammonia is poisonous in high concentrations. But as we’ve discussed, it does have its own stench — and that, on some level, is the point. Pair that with the right safety protocols and workforce training, they argue, and the risks are dramatically reduced.
• Operating Pressures: The pressures of operation for CO2 systems are significantly higher than those for conventional systems. That also means you need specialized equipment designed to withstand that pressure, complicating a retrofit of older systems. But this also releases those efficiency gains we referred to.
• Costs in the Short Term: Although natural refrigerant systems generally have lower lifetime costs, the upfront expense to purchase specialized equipment and the training that your team will require can be higher at times. Think of it as spending more on high-quality equipment, which is worth the high cost to buy at the outset because it works better and lasts longer.
• Workforce Training: There’s a learning curve. There is a lack of adequately trained personnel for natural refrigerant systems that can be a bottleneck. But organizations including the North American Sustainable Refrigeration Council (NASRC) are moving on the bridging aspect of that gap.
• Material Compatibility: Speaking of that there ammonia not like-and-a copper in such things. These are important design considerations, but they are not insurmountable.

The Unsung Hero in Your System. Lubricant Lubricant – we all agree it’s a good thing!

You wouldn’t drive your car without oil, would you? Refrigeration systems: Ditto. The compressor requires lubrication and that lubrication must be compatible with the refrigerant you will be using. And when it’s not, you really mess up heat transfer and get the compressor to do things you don’t want it to do.”

• Hydrocarbons: Require ultra low solubility lubricants such as polyalkylene glycol (PAG) and polyalphaolefin (PAO), as the typical mineral oils have high solubility tendencies.
• CO2: CO2 is a stronger solvent than most HFC’s and traditional oils don’t work. You are often going to use a specialized POE to take the higher stresses and higher pressures.
• Ammonia: Needs lubricants with high oxidation related resistance, fluidity and low operating temperatures as well as with viscosity. Under these circumstances, it would be the job of a PAO or PAO/AB blend.

It’s a small thing, but a big one. Get it wrong, and your system will do you little good.

The Front Runners : Who’s Already at Work With Natural Refrigerants

This isn’t some theoretical exercise; it’s unfolding. The change is being pushed by big players and inventive organisations.

• GEA: A large systems supplier in food, beverage, and pharma, GEA is firmly in the natural refrigerant camp. They are pulling the switch with webinars and a focus on future-proof, energy-saving solutions.
• True Manufacturing: These dudes are the real deal. They use ONLY hydrocarbon refrigerants in all of their units. It’s not all lip service as they’re on track to be a Zero Waste Facility by 2027 and are also using solar power to help offset carbon emissions. They have even received the 2024 ENERGY STAR Partner of the Year Award. That’s a flex.
• Better Buildings Initiative (U.S. Department of Energy): The Better Buildings Initiative is an invaluable resource for unlocking the door for the future adoption of natural refrigerants. They’re about handing you the playbook.
• North American Sustainable Refrigeration Council (NASRC): It’s a not-for-profit firm, a mission-based organization working to advance natural refrigerants that are climate-friendly, and especially in supermarkets that are so ubiquitous. They are compiling a resource library to assist industries that want to transition.
• ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers): These are the people writing the rules. ASHRAE funds research, writes standards, and advocates the responsible and safe use of natural refrigerants. They openly acknowledge that natural refrigerants are part of the solution to growing cooling needs in a sustainable way.”
• Kalos Services: Offers natural refrigerant installation education to demonstrate how companies are applying knowledge.

This is no niche experiment. It’s a full-blown industry shift, supported by serious players.

Bottom Line: Your Future is Looking Au Natural!

Well, the writing is on the wall. Climate change is increasing demand for smarter cooling, and those old synthetic refrigerants simply aren’t cutting it anymore. Regulations are phasing them out, and the market is asking for better.

So natural refrigerants are hot stuff. They’re sustainable, environmentally friendly and, if you crunch the numbers, generally cost-effective in the long run. They are a future-proof investment that is compatible with global sustainability objectives and that strengthens your business. It’s not just having to comply, it’s the smart business decision that’s good for everybody. The future of refrigeration is green, and it’s natural refrigerant.

FAQs: Direct Answers to Boiling Questions on Your Mind

Q: Why are natural refrigerants ”natural” with and are they truly “natural”? A: That’s because they’re known as natural refrigerants, meaning they are substances that are found directly in nature, including ammonia, carbon dioxide and hydrocarbons (such as propane and isobutane). They are industrial substances used in cooling systems, but they contain natural elements.

Q: Can we safely use natural refrigerants? A: Yes, natural refrigerants are safe when used in the right way: If the system is well designed, properly installed and well maintained. Each type also carries specific safety issues (flammability in the case of hydrocarbons, toxicity in the case of ammonia). But industry has decades of experience with these substances, established safety thresholds and technology in place to minimise risk.

Q: Are natural refrigerant systems more costly at the get-go? A: The upfront costs for equipment and training in systems that use natural refrigerants can sometimes be higher. Yet, when you consider the entire life cycle – from energy use to extending availability long after the original purchase – more often than not natural materials wind up the least costly over time compared to their synthetic counterparts.

Q: Can my exisiting refrigeration system be converted into a natural refrigerant system? A: It depends. Very high operating pressures are associated with some natural refrigerants, such as CO2 – so high in fact, that systems on the market today, simply cannot be retrofitted and require special new equipment. But some applications or natural refrigerant types could enable a switch, particularly in smaller, self-contained units. Best to ask an expert in the field.

Q: What is GWP and ODP and why does it matter? A: GWP is an abbreviation for Global Warming Potential, and ODP is an abbreviation for Ozone Depletion Potential. GWP, which stands for global warming potential, is a measure of the impact a refrigerant has to global warming as compared to carbon dioxide (which has a GWP of 1). ozone depletion potential (ODP) a measure of a refrigerant’s ability to degrade the ozone layer compared with R-11 (being 1). They matter; refrigerants can be released into the atmosphere, and these metrics help measure their impact on the environment. The natural refrigerants have low-to-no GWP, no ODP, and are environmentally friendly.