Natural Refrigerants on the Rise: Ammonia

The commercial refrigeration industry stands at a critical juncture. As regulatory pressure mounts on synthetic refrigerants and sustainability becomes a business imperative, ammonia and other natural refrigerants are the current choice of many customers as they look to plan their capex plans for the coming years.
We met again with our Cooling Tech Divisional Director, Mathew Noon, to find out more about this global shift toward ammonia refrigeration and what it means for the industry.

What’s driving the renewed interest in natural refrigerants like ammonia?

“We’re witnessing a perfect convergence of regulatory pressure, environmental awareness, and economic reality. But it’s not just about compliance, organisations are recognising that investing in HFC-dependent systems today means facing stranded assets, escalating refrigerant costs, and technological obsolescence within a system’s normal lifecycle.
What’s particularly interesting is that this isn’t new technology we’re talking about. Ammonia has been used in refrigeration since the 1850s. We’re essentially returning to proven chemistry, but now we can combine it with modern engineering and safety systems that make it more viable than ever.”

What is the difference between Ammonia and CO2?

“That’s an excellent question because both are natural refrigerants with extremely low GWP, but they have very different characteristics and optimal applications.
Ammonia operates at much lower pressures than CO₂—we’re talking standard refrigeration pressures versus CO₂ systems that can operate at 80 to 100 bar or higher, especially in transcritical applications.
From a thermodynamic efficiency standpoint, ammonia typically delivers superior performance in large industrial systems, particularly at lower temperatures. It has excellent heat transfer properties and energy efficiency across a wide operating range. CO₂ systems can be very efficient too, especially in certain configurations, but they’re more sensitive to ambient conditions – high outdoor temperatures can significantly impact CO₂ system efficiency.
In terms of applications, we tend to see ammonia chosen for large industrial facilities where efficiency, proven track record, and typical lower operating costs provide advantages. CO₂ has found strong footing in retail refrigeration, smaller commercial applications, and as a secondary refrigerant in cascade systems with ammonia as the primary refrigerant. That cascade approach actually combines the benefits of both – ammonia’s efficiency in the main system with CO₂ providing safe, efficient cooling in occupied spaces.”

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Where do you see Ammonia refrigeration heading?

“The trajectory is clear: ammonia has always been, and will continue to be, a core part of industrial cooling.
Rather than a shift, what we’re seeing is a continued reliance on a proven, well-understood refrigerant that forms the backbone of industrial refrigeration. Regulatory frameworks and modern engineering practices ensure it remains a safe, efficient, and viable solution when designed and maintained correctly.
For organisations planning refrigeration investments, ammonia continues to offer a dependable, future-ready option built on more than a century of proven performance.”