Which Liquid is Commonly Used as a Cheap Refrigerant in Cold Storage Facilities?

Among the options available, ammonia (NH3) stands out as a popular and cost-effective refrigerant for large cold storage facilities. Ammonia is renowned for its high energy efficiency and low cost compared to other refrigerants, making it a favored choice in industrial applications such as food processing and cold storage. ammonia systems are particularly valued for their capability to achieve low temperatures and their minimal environmental impact when managed properly.

Ammonia: The Preferred Refrigerant for Industrial Applications

For large cold storage facilities, ammonia has become the refrigerant of choice due to its superior performance in terms of the net refrigerating effect (btu/lb) and brake horsepower per ton of refrigeration (BHP/TR). However, it is crucial to note that ammonia is toxic and requires careful handling and safety measures to prevent accidents. Despite this, the system's overall efficiency and cost-effectiveness make it a valuable option in many industrial settings.

The Toxic Nature of Ammonia

Ammonia is widely recognized as a toxic substance, but its benefits cannot be ignored. Its distinctive smell, which is often described as unpleasant and pungent, serves as an early warning to personnel in case of high concentrations. In ideal conditions, humans can detect ammonia vapors in the air at concentrations as low as 20 parts per million (ppm). At 100 ppm, moderate irritation to the nose begins to occur, and at 400 ppm, major irritation is likely. Nevertheless, unless incapacitated by other means, individuals will generally quickly evacuate any area where an ammonia leak or spill has occurred before IDLH (immediate danger to life and health) levels are reached.

Alternatives to Ammonia: Ethylene Glycol

While ammonia remains a preferred choice for many cold storage facilities, its toxicity makes it less suitable for certain applications. In those cases, ethylene glycol is often considered as a viable alternative. Ethylene glycol is commonly used in motor vehicle coolant and is widely available under brands like Prestone and Zerex. This coolant is non-corrosive to metal pipes, has a very low freezing point, and is an effective refrigerant in cold storage settings.

Selecting an Appropriate Refrigerant

When choosing a refrigerant for cold storage facilities, several key factors must be considered:

Toxicity: Is the refrigerant safe for the environment and personnel? Chemical Properties: Is it non-corrosive to metal pipes? Freezing Point: Can it achieve the required low temperatures?

Ethylene glycol, for instance, meets these criteria effectively, making it a reliable alternative to ammonia in certain applications. Its use in motor vehicle coolants demonstrates its effectiveness in maintaining a low freezing point while being non-corrosive.

Conclusion

While ammonia is a highly effective and cost-efficient refrigerant for cold storage facilities, its toxicity necessitates stringent safety measures. Ethylene glycol, on the other hand, offers a safer alternative that meets many of the same performance needs. As such, both refrigerants play a crucial role in maintaining the efficiency and safety of cold storage facilities, ensuring the preservation of food and other temperature-sensitive products.