Ammonia chiller: How It works, benefits and industrial applications

An ammonia chiller is one of the most efficient and environmentally friendly refrigeration technologies used in industrial cooling today. By using ammonia (R717) as a refrigerant, these systems provide high-performance cooling while minimizing environmental impact and operating costs. As industries seek sustainable alternatives to synthetic refrigerants, ammonia chillers continue to gain importance across food processing, chemical manufacturing, district cooling, and large-scale industrial facilities.

Let’s take a look at what exactly is an ammonia chiller, how it works and its benefits.

What is an ammonia chiller

An ammonia chiller is a type of refrigeration system that uses ammonia as the refrigerant to absorb and remove heat from a space or a process. As we’ve mentioned above, it’s become a common option for industrial and commercial settings where large amounts of heat need to be transferred and dissipated.

How does an ammonia chiller work

The working principle of an ammonia chiller follows basic physics so that heat can be moved out of an area and into another, effectively making the first one cooler. 

• First, an evaporator is employed, an area where ammonia is allowed to evaporate at low pressure and low temperature. This process means heat is absorbed from the surrounding environment.
• Then, the ammonia vapor is compressed by a compressor, which increases its pressure and temperature. This translates into raising the energy level of the ammonia.
• The high-pressure, high-temperature ammonia vapor is then condensed in a heat exchanger or condenser, where it releases the heat is absorbed during the previous evaporation process. 
• Finally, after condensation, the high-pressure liquid ammonia is expanded through an expansion valve, which reduces its pressure and temperature. This causes it to partially vaporize, so that it can return to the evaporator to start the cycle again.

The benefits of using an ammonia chiller 

• Efficiency: the thermodynamics and physical properties of ammonia make it an efficient refrigerant, particularly when incorporated to large ammonia systems.  Its excellent thermodynamic properties include a high latent heat of vaporization and good heat transfer characteristics. These properties make ammonia chillers highly efficient in transferring heat and providing effective cooling. As such, an ammonia chiller can achieve the same cooling effect while employing less energy, cutting down on operational costs. 
• Sustainability: ammonia represents a more environmentally-friendly option than synthetic refrigerants such as CFCs, some of which have been banned for their environmental damage. Ammonia breaks down quickly and doesn’t damage the ozone layer. In fact, ammonia has a zero ozone depletion potential (ODP) and a low global warming potential (GWP). This means it doesn’t have a significant impact on climate change, making an ammonia chiller an environmentally friendly choice.
  As such, it’s able to meet strict refrigerant guidelines targeting other polluting products. As such, ammonia chillers meet or exceed regulatory requirements for safety and environmental standards, helping operators stay in compliance with local and international regulations.
• Safety: ammonia spills or leaks (even when small) are easily detected thanks to this element’s strong odor. 
• Costs: ammonia is relatively inexpensive compared to some other refrigerants. This adds up to making the ammonia chiller a cost-effective choice for large-scale cooling systems.
• Reliability: the ammonia chiller is known for its durability and reliability when properly maintained. They often have a longer lifespan compared to other types of chillers, reducing the need for frequent replacements and associated costs. Additionally, when properly maintained, ammonia chillers often have lower maintenance costs compared to some other refrigeration systems, and are less prone to issues like refrigerant leakage.
• Versatility: ammonia chillers can be used in various applications. In fact, they have become outstandingly popular in multiple sectors, including industrial refrigeration, food processing, chemical manufacturing and HVAC systems in large commercial buildings.
• Rapid and efficient cooling: ammonia's excellent heat transfer properties make it suitable for applications that require rapid and efficient cooling. This includes complex large-scale manufacturing processes.

It's worth noting that ammonia is toxic and flammable. This means any ammonia chiller must be carefully designed, installed and maintained, only relying on professional experts that are able to verify each step of the way.

Additionally, ammonia chiller systems require strict adherence to safety regulations to prevent accidents and exposure to the gas. Again, careful design, management and maintenance can reduce these risks substantially.

Ammonia Chiller vs Synthetic Refrigerant Chillers

When evaluating industrial cooling technologies, one of the most important considerations is the choice of refrigerant. Ammonia chillers are often compared with systems that use synthetic refrigerants, particularly HFCs, due to their differences in environmental impact, efficiency, operating costs, and long-term regulatory outlook. The following comparison highlights some of the key factors that make ammonia an increasingly attractive option for large-scale cooling applications.

ARANER's approach to ammonia chiller solutions

At ARANER, we work to develop district cooling systems that are sustainable without compromising their cost-efficiency. Our engineering teams evaluate each project's thermal requirements to develop energy-efficient and environmentally responsible cooling systems that maximize performance while reducing operating costs.

As part of our vision to generate the most adequate cooling strategy for each project, we often consider ammonia chiller options and their benefits. 

Get in touch with us to speak to our team about the best cooling option for your project.

Frequently Asked Questions about ammonia chillers

What is an ammonia chiller?

An ammonia chiller is a refrigeration system that uses ammonia (R717) as a refrigerant to remove heat from industrial processes, buildings, or cooling networks. It is widely used in large-scale cooling applications due to its efficiency and sustainability.

How does an ammonia chiller work?

An ammonia chiller transfers heat through a cycle of evaporation, compression, condensation, and expansion. This process allows heat to be removed efficiently from the area or process being cooled.

Why is ammonia used in industrial chillers?

Ammonia offers excellent heat transfer properties, high energy efficiency, and low refrigerant costs, making it ideal for industrial refrigeration and cooling systems.

Are ammonia chillers environmentally friendly?

Yes. Ammonia has zero Ozone Depletion Potential (ODP) and an almost negligible Global Warming Potential (GWP), making it a sustainable refrigerant choice.

Are ammonia chillers safe?

When properly designed and maintained, ammonia chillers are safe to operate. Modern systems include leak detection, ventilation, and other safety measures to minimize risks.

What industries use ammonia chillers?

Ammonia chillers are commonly used in food processing, cold storage, chemical manufacturing, district cooling, and other industrial refrigeration applications.

What are the advantages of ammonia chillers compared to HFC chillers?

Ammonia chillers typically offer higher efficiency, lower refrigerant costs, and a lower environmental impact than systems using HFC refrigerants.

How long does an ammonia chiller last?

With proper maintenance, an ammonia chiller can operate reliably for 20 years or more, making it a durable long-term cooling solution.