Ammonia-based air conditioning, also known as ammonia refrigeration or ammonia HVAC systems, has some advantages and is used in certain applications. However, it is not as commonly used as other refrigerants like hydrofluorocarbons (HFCs) due to several reasons:
Toxicity and Safety Concerns: Ammonia is a toxic and potentially hazardous substance. While it has been used safely in industrial refrigeration and some large-scale HVAC systems, its use in smaller residential or commercial applications is limited due to safety concerns. Leakage or mishandling of ammonia can pose health risks to occupants and technicians working with the system.
Regulatory and Environmental Factors: Ammonia has a relatively high Global Warming Potential (GWP) compared to some modern HFC refrigerants. While it is a natural refrigerant and does not contribute to ozone depletion, its GWP makes it less environmentally friendly than some low-GWP HFC alternatives. As environmental regulations continue to evolve, some countries or regions may limit the use of ammonia in certain applications.
System Complexity: Ammonia refrigeration systems are more complex to design, install, and maintain compared to conventional HFC-based air conditioning systems. They require specialized expertise and equipment, making them less accessible for widespread use.
Corrosion Concerns: Ammonia is corrosive to certain metals, which can limit the choice of materials that can be used in the construction of the system. This can increase the cost and complexity of manufacturing and maintaining ammonia-based HVAC systems.
Efficiency Differences: While ammonia is a good refrigerant in terms of thermodynamic properties, its overall system efficiency may be slightly lower than some modern HFC refrigerants, which have been optimized over the years for specific HVAC applications.
Public Perception: The general public may have reservations about the use of ammonia in air conditioning systems due to its historical association with accidents or incidents in industrial settings.
Despite these challenges, ammonia remains a popular choice in large industrial refrigeration applications, such as cold storage facilities, food processing plants, and ice rinks. In these contexts, the advantages of ammonia, including its excellent heat transfer properties and energy efficiency, outweigh the concerns.
As the HVAC industry continues to explore more environmentally friendly and energy-efficient refrigerants, there may be ongoing research and development to address some of the limitations of ammonia-based air conditioning systems. However, for now, ammonia remains less prevalent in conventional residential and commercial air conditioning due to the factors mentioned above.