Choosing Between Ammonia and Freon in Industrial Refrigeration Systems

The decision between using ammonia or Freon in the refrigeration cycle is a crucial one, fraught with its own set of advantages and disadvantages. It’s a question that often weighs heavily on the minds of those involved in constructing industrial refrigeration facilities. Unfortunately, many owners of refrigeration complexes have faced challenges in making this decision, leading to issues during system operation. This article aims to provide a comprehensive, unbiased review of the factors at play in this decision-making process. By exploring the strengths and weaknesses of both options, stakeholders can make informed choices that align with their specific needs and priorities in refrigeration system design and operation.

The Future of Freon: Phasing Out or Evolving?

While traditional Freon refrigerants are being phased out due to environmental concerns, newer alternatives, often referred to as “New Freons,” are emerging as valuable solutions in modern refrigeration systems.

There’s an old saying: “Everything has its purpose,” and this holds true for refrigerants as well. Different refrigerants excel in different applications. For example, ammonia is widely used in industrial refrigeration, particularly in the food and beverage industry. However, since the early 20th century, Freon-based cooling has been an integral part of this sector, complementing other systems.

Although the last true Freon, R22, will be phased out from new equipment markets next year, alternative refrigerants approved by the U.S. Environmental Protection Agency (EPA) continue to serve a critical role in refrigeration, demonstrating that Freon technology still has a future in the industry.

The Key Differences Between Ammonia and Freon in Refrigeration

The primary difference between ammonia and Freon lies in their origins, applications, and efficiency. Ammonia, a natural refrigerant, has been in use since the early days of refrigeration, particularly in industrial settings. While ammonia is toxic, its strong odor acts as a self-warning system in case of leaks, and it remains highly efficient in heat transfer. Freon, on the other hand, is a synthetic refrigerant developed to replace ammonia and sulfur dioxide, offering less toxicity and greater ease of use in commercial and residential systems. However, Freon is slightly less efficient than ammonia on a BTU per pound basis, especially in larger industrial applications where ammonia systems often use open drive compressors and evaporative condensers for better performance at low temperatures.

System Design and Performance Considerations

In terms of system design, ammonia systems are generally more efficient when paired with evaporative condensers, which operate at lower pressures. Freon systems, commonly found with hermetic or semi-hermetic compressors and air-cooled condensers, tend to transfer more heat to the cooling system, impacting overall efficiency.

Freon in Specialized Applications

Freon can be more suitable in certain applications, like small sub-zero cold rooms or environments where ammonia leaks could pose quality risks, such as nut storage. Another critical factor is the regulatory environment. Ammonia systems require stricter oversight and specialized operators, and some regions limit their use due to safety concerns.

Environmental Impact of Ammonia and Freon

Lastly, in terms of environmental impact, ammonia is eco-friendly, breaking down into nitrogen and hydrogen, while older Freon types contribute to global warming, although newer alternatives have less harmful effects. Lastly, in terms of environmental impact, ammonia is eco-friendly, breaking down into nitrogen and hydrogen, while older Freon types contribute to global warming, although newer alternatives have less harmful effects.

Split Freon Systems in Refrigeration

Traditionally, most Freon refrigeration units operate as split systems, with the evaporator and condenser positioned closely together to minimize piping and refrigerant costs. In these systems, the evaporator is typically ceiling or window-mounted near the condenser. Since they are direct expansion (DX) systems, maintaining proper head pressure is crucial for the expansion valve’s required pressure differential. Head pressure control is managed by adjusting condenser fan ventilation.

In larger installations, several condensers may be distributed across the roof. Some setups utilize a rack system, which involves multiple reciprocating compressors operating at various suction levels to balance the load. These rack systems can be water-cooled, air-cooled, or cooled with evaporative condensers, depending on the application.

Properties of Ammonia Gas in Refrigeration Systems

Ammonia, with the chemical formula NH3 and refrigerant code R-717, boasts a robust presence in the refrigeration industry, making it a staple choice for most industrial refrigeration facilities. Below, we delve into some key properties of ammonia gas within refrigeration cycles.

The Odor of Ammonia Gas

One of the primary attributes of ammonia gas is its pungent odor, facilitating easy detection and prompt resolution of any system leaks. Inhalation of high concentrations of ammonia gas in the environment can lead to symptoms such as severe burning and itching of the eyes, nose, and throat, necessitating the use of masks with three-mode filters in affected areas. Prolonged exposure to high concentrations of this gas can result in respiratory issues. For further guidance, please refer to the ammonia first aid instructions.

Ammonia Gas Price Comparison

Ammonia gas is considerably more cost-effective compared to freon gas. Moreover, detecting leaks in ammonia systems is typically easier due to the distinctive odor it emits, facilitating quicker repairs and reducing the need for frequent recharges. It’s important to highlight that the cost of one kilogram of freon gas is nearly 30 times higher than that of ammonia gas.

Environmental Impact of Ammonia Gas

Ammonia gas, being lighter than air, naturally ascends within a space. It is inherently non-flammable and non-combustible under regular conditions, except at elevated temperatures and concentrations. Ammonia is environmentally safe and does not contribute to ozone layer depletion or global warming. However, it’s crucial to note that uncontrolled release of ammonia gas into the environment can lead to significant harm to vegetation and trees in the vicinity. Proper handling and containment are essential to mitigate any potential environmental risks associated with ammonia gas.

Thermodynamic Properties of Ammonia Gas

Ammonia gas boasts superior thermodynamic properties compared to freons, presenting a notable advantage. In equal conditions, ammonia exhibits a significantly higher specific heat property than freon, resulting in a potential reduction of electricity costs by up to 20% when using this refrigerant. Additionally, the broader temperature range achievable with ammonia further enhances its appeal over freon, making it a favorable choice for various refrigeration applications.

Advantages and Disadvantages of Freon Family Refrigerants | Ammonia or Freon

Exploring the distinct characteristics of Freon family refrigerants versus ammonia allows for a comprehensive understanding of their advantages and disadvantages. This comparison facilitates informed decision-making regarding the choice between ammonia and Freon refrigerants in various applications. Understanding the unique properties, environmental impacts, efficiency, and safety considerations of each refrigerant type is crucial for optimizing refrigeration systems while mitigating potential drawbacks.

Simple System and Management of Freon Systems

Halocarbon gases, commonly known as freons, are often employed in simpler refrigeration systems, necessitating fewer safety precautions. In freon-based cold storage facilities, operator intervention and routine maintenance are typically minimal, with the system operating semi-automatically. This streamlined operation is widely regarded as a significant advantage, particularly in commercial-scale freon systems where simplicity and efficiency are paramount.

Freon: Odorless and Costly

Freon, a member of the halocarbon family, is nearly odorless, making it challenging to detect leaks until significant gas loss occurs. The absence of a distinctive odor increases the risk of complete gas discharge from the system, resulting in substantial costs for owners.

Environmental Impact of the Freon Family

The Freon gas family encompasses various types categorized by their environmental effects. Older gases like R-11, R-12, and R-22 significantly contribute to ozone layer depletion and global warming. In contrast, newer gases such as R-404A and R-134A pose relatively less harm to the ozone layer. Despite advancements, the colorless and odorless nature of freons complicates leak detection, exacerbating their environmental impact compared to ammonia. Thus, while newer freons are less harmful, the environmental damage caused by this refrigerant family remains a concern.

Additional Properties of Freons

Freon refrigerants demonstrate compatibility with copper, a commonly used material in heat exchanger fabrication. Furthermore, the use of freons allows for the utilization of semi-hermetic compressors, as these refrigerants do not react with the copper coils of the electromotor. However, it’s worth noting that semi-hermetic compressors have a relatively shorter lifespan compared to open compressors, which is a potential drawback despite the benefits of using freons.

Conclusion on Ammonia or Freon

In conclusion, when considering the technical and financial aspects, Freon refrigerants find their justification in commercial and air conditioning units, and in certain semi-industrial settings. However, when it comes to industrial applications, the use of ammonia refrigerants stands out as both technically and financially justified. Ammonia offers superior thermodynamic properties, cost-effectiveness, and environmental friendliness compared to Freon, making it the preferred choice for industrial refrigeration systems. Its effectiveness in large-scale industrial units makes it a highly viable option for those seeking efficient and sustainable refrigeration solutions