Ammonia refrigeration refers to the use of anhydrous ammonia (NH₃) as a refrigerant within industrial cooling systems. Unlike synthetic refrigerants, ammonia is a naturally occurring compound with excellent thermodynamic properties. It has been widely used for over a century in large-scale cooling applications thanks to its efficiency and environmental credentials.
As a refrigerant, ammonia can absorb significant amounts of heat, making it ideal for operations requiring consistent temperature control. It is not commonly used in residential or small commercial systems. However, for larger facilities where industrial refrigeration is needed, it offers a reliable, long-term cooling solution. Ammonia refrigeration systems must be designed and maintained carefully, but when handled correctly, they offer both economic and environmental advantages over synthetic alternatives.
How Ammonia Refrigeration Systems Work
Ammonia refrigeration systems operate using a closed-loop cycle comprising four key stages: compression, condensation, expansion and evaporation. In the evaporator, liquid ammonia absorbs heat from the surrounding environment and changes into a vapour. This vapour is then compressed, raising its pressure and temperature before it enters the condenser, where it releases heat and returns to a liquid state.
The liquid ammonia then passes through an expansion valve to lower its pressure and repeat the cycle. Ammonia’s ability to absorb large amounts of heat makes this process highly efficient. Advanced systems may also feature oil separators, purging systems and secondary cooling loops to enhance safety and efficiency. Overall, the design is geared toward maximising performance while managing ammonia’s hazardous properties.
Where Is Ammonia Refrigeration Used?
Ammonia refrigeration is typically found in industries that require substantial and consistent cooling performance. It is commonly used in food processing plants, beverage production facilities and chemical manufacturing centres as well as for warehouse cooling. Large logistics hubs, abattoirs and dairy operations also rely on ammonia to maintain strict temperature controls.
Its high energy efficiency and reliable thermal performance make it suitable for 24/7 operations where downtime or fluctuation in temperature can compromise safety, compliance or product quality. In some specialist applications, such as ice rinks or blast freezers, ammonia systems are preferred for their rapid cooling capacity and operational stability. While not suited to every environment, ammonia is trusted across sectors where high-volume, cost-effective cooling is essential.
Pros of Using Ammonia as a Refrigerant
One of ammonia’s key advantages is its outstanding energy efficiency. Its high latent heat of vaporisation allows it to transfer more heat per kilogram than most synthetic refrigerants, reducing energy consumption and operational costs. Ammonia has zero ozone depletion potential (ODP) and a global warming potential (GWP) of zero, which makes it one of the most environmentally responsible refrigerants available.
What’s more, it is also naturally occurring and widely available, making it cost-effective over the long term. Because ammonia systems are generally robust and built for industrial use, they offer long service lives when maintained properly. Combined with efficient performance and low environmental impact, these benefits make ammonia a preferred choice in sectors prioritising sustainability and lifecycle cost savings.
Cons and Safety Considerations
Despite its strong performance and environmental profile, ammonia presents certain safety challenges. It is toxic when inhaled in high concentrations and corrosive to some metals, which means systems must be designed with safety at the forefront. Leak detection sensors, emergency shutoff valves and proper ventilation are essential components in any ammonia installation. Ammonia’s odour acts as a natural warning, but it can still pose risks if not managed properly.
Due to these concerns, regulatory compliance and thorough operator training are crucial. Although modern systems have advanced safety features and monitoring technologies, ongoing maintenance and inspection are vital. These additional requirements mean that while ammonia systems can deliver excellent long-term value, they also demand a higher level of oversight and responsibility.
Ammonia Versus Other Refrigerants
Compared with synthetic refrigerants, ammonia offers a significantly lower environmental impact and better energy efficiency. Ammonia systems tend to be more efficient at lower temperatures, which makes them ideal for industries requiring deep-freeze applications. In contrast, synthetic refrigerants are often easier to handle and require less specialised training, but they can be more expensive in the long term due to environmental regulations and higher energy use. CO₂ is another natural alternative, but it operates under much higher pressures and can be more complex to manage.
Is Ammonia Refrigeration Right for Your Business?
Ammonia refrigeration is ideal for businesses that need reliable, large-scale cooling with minimal environmental impact. It’s particularly suited to sectors such as food production, pharmaceuticals and warehouses. However, it does require proper infrastructure and maintenance investment. If you’re considering ammonia for your next project, TJ Refrigeration can help assess suitability and deliver a safe, efficient system tailored to your operational needs.
