Comparing HFO-based systems to ammonia for process cooling

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Published: 07 October 2021


Dave Palmer, general manager for UK and Ireland at ICS Cool Energy, highlights the considerations that the food and beverage industry must take to transition to low GWP, HFO-based cooling systems.

For the manufacturing industry, the importance of high performing, energy-efficient and sustainable process cooling solutions is, of course, nothing new. Manufacturing companies need to balance the rising costs and energy emissions of the plant while at the same time maintaining product quality and process efficiency. This is particularly important in processes such as food and dairy manufacturers, breweries, soft drinks production, and chemical and pharmaceutical industries, where manufacturers must live up to a plethora of standards and regulations related to the quality of the end products. 

As with all stringent standards, they add to costs, energy consumption and ultimately make life harder for people looking for ways to reduce the Total Life Cycle Cost of their investments. In addition, reducing the emissions and energy use of operations is also under the increased attention of policymakers, adding to the pressures of the manufacturing industries.

New ways for quality process cooling

This all serves to focus the attention of the process cooling industry to drive innovation and meet the call for new ways of providing quality, high-performing and sustainable process cooling. As a result, new technologies and techniques emerge that allow companies to contain their costs without compromising other critical factors.
 
One of the trends is moving away from ammonia-based cooling systems. Ammonia has been traditionally common in food and beverage processing applications due to its cooling capabilities and low global warming potential (GWP) qualities. Yet, repetitive incidents with leaks threatening workers’ health and causing potential end-product and environmental contamination have triggered a discussion on the pros and cons of using ammonia as a refrigerant. 

With ammonia’s toxicity causing severe health risks from even a low-level leak, the process cooling industry has responded with substantial improvements in technology. These improvements offer manufacturers a viable alternative to the ammonia-based systems – removing the risks, adding better energy efficiency, and lowering the cost of ownership.

HFO refrigerants: R1234ze systems for low GWP, lower cost, no toxicity and easy maintenance 

When considering ammonia-based systems’ risk factors, process cooling systems with hydrofluoroolefin (HFO) refrigerants create a vital, safer, more energy-efficient option with equally low environmental impact. But it’s the plant and operations managers who need to make a choice and select a system that will be best for their application, future-proofing their operations for years to come. 

Looking at the two alternatives, there are six main criteria to compare a system with an HFO refrigerant, like the R1234ze, to an ammonia-based solution:

1.    The Global Warming Potential
To reach our overall sustainability targets and become carbon-neutral societies, we cannot neglect the Global Warming Potential (GWP) of the refrigerants used in the cooling systems. 

The R1234ze HFO is an ultra-low, near zero GWP fluid with a GWP of less than 1, which means it has a lower impact on global warming than CO2. Ammonia has a GWP of 0, which makes the two fluids very comparable from this perspective. What stands out for the R1234ze is that it enables customers to reduce their carbon footprint without sacrificing performance. Moreover, chillers with R1234ze refrigerant can outperform ammonia by 25 per cent according to the energy efficiency ratio (EER) analysis.

2.    First cost
Successful and economically sustainable businesses know that they need to make investment decisions to protect their viability. When comparing the initial investment in a process cooling system, we realise that ammonia solutions can be significantly more expensive.

Higher costs of an ammonia system stem from the hours spent designing it, the expensive stainless-steel piping required to withstand ammonia’s corrosive properties, and special devices mounted and needed to monitor the safety of the system. However, standard design, production and components allow manufacturers to offer HFO-based systems at a much lower cost. We should also realise that standardised HFO chillers are usually smaller than the ammonia systems, and thus locations, where equipment footprint might be an issue can also save space thanks to the more compact design.

When it’s not the right time for capital investments, manufactures can now also benefit from a new type of subscription offering that gives them access to the latest process cooling equipment with the flexibility of an operating expense. With subscription models like the FLEX Membership manufacturers can now transform their process temperature control system from a fixed asset into a dynamic solution that will be up to date with their changing business and process needs. This means that there is no upfront cost and capital investment. The membership package includes a complete process temperature control solution: equipment, preventive and 24/7 emergency maintenance, replacements, and upgrades – all as part of a monthly rate contract tailored to the process’ needs. 

3.    Toxicity 

The safety of people and our environment shouldn’t be taken lightly. For example, it is well known that ammonia is highly toxic. When leaking from a system, it can pose severe risks to human health and food and beverage or pharmaceutical operations. R1234ze, on the other hand, is a non-corrosive substance with very low toxicity and mild flammability. 

4.    Maintenance

Regular maintenance will always be needed on any process cooling system, but some systems are easier to maintain than others. Because of its toxic properties, when handling ammonia or performing maintenance on ammonia systems, facility managers and technicians must take very stringent safety precautions and anticipate and manage the risks to people and the surroundings.

However, on a system with R1234ze, maintenance can be performed with limited risks. If the original equipment manufacturer maintains a system, then facility and operations managers have the peace of mind that it is carried out by technicians, who are fully trained on the safe maintenance of HFO refrigerant systems.

5.    Lead time

Lead time can make a big difference. Standardised products with standardised components open the door to shorter lead times and quicker deliveries, allowing for the appropriate system with R1234ze to be delivered on short notice. 

Non-standardised products like ammonia-based systems take longer to design and manufacture before they can be shipped and installed.

6.    Performance

The last but equally important criterion to consider is performance. Standardised products such as chillers with R1234ze have underdone rigorous R&D procedures to offer the best possible performance and efficiency. In addition, standardisation allows the units to be tested and certified by third parties to prove their catalogue performance is genuinely delivered. 

So far, no ammonia systems have been certified by third-party organisations like Eurovent or the Air-Conditioning, Heating, and Refrigeration Institute (AHRI). This means that manufacturers can only see if it achieves the performance as promised after the entire ammonia system has been installed and is running.

In conclusion, modern, innovative systems with R1234ze that are purposefully designed for process applications have clear advantages compared to ammonia-based systems. When specifying their process cooling equipment, manufacturers should carefully examine all the options available on the market to ensure they will fully benefit from their new cooling equipment for the years to come.