Refrigerants are chemical compounds that are engineered to work as cooling agents in refrigerators, freezers, display cases, merchandisers, and many other commercial refrigeration equipment to keep meat, poultry, fish, vegetables, fruits, and other perishables safe and fresh.
Refrigerants have primarily three features in common, which enable them to provide the desired cooling for any environment:
- Specific thermodynamic and chemical features for enhanced heat exchange,
- Non-corrosive nature to protect components,
- Non-toxic, non-flammable formula for higher safety.
Refrigerants enable cooling through a continuous cycle of refrigerants! Plying between the liquid and gaseous form. The refrigerants start the cycle in liquid form and change into gas in the expansion valve. While this gas refrigerant passes in the evaporator coil, it absorbs the heat from the environment. The condenser removes the gas that absorbs the heat, and this heated gas passes through the condenser coil, turning into liquid form and emitting the heat to the atmosphere.
Food preservation has always been a problem for humanity, and people developed many ways of storing foods by salting, smoking, or drying. Refrigeration marks an actual revolution in the food industry since it allows the preservation of perishable and sensitive food materials over long distances and for much longer durations. Refrigeration systems that used natural refrigerants were first developed in the 1800s when Michael Faraday developed absorption refrigeration in 1824. Later, turning the use of carbon dioxide and propane, the refrigeration industry still needed secure refrigerant options since these earlier compounds were dangerous and flammable.
Thomas Midgley Jr. developed the first synthetic chlorofluorocarbon (CFC) R-12, or “Freon,†in 1938. Since it is not flammable or toxic, it soon gained a wide market share and widespread use in the refrigeration industry.
However, the CFCs were very harmful to the environment due to their damage to the Ozon Layer, which was discovered in the 1980s. So, the refrigerant industry entered a new phase of tighter regulations and constraints after the Vienna Convention for the Protection of the Ozone Layer was approved in 1985 to regulate the production of ozone-depleting materials, as explained in academic research. The Montreal Protocol of 1987 brought radical limitations on using and producing CFCs and Hydrochlorofluorocarbons (HCFCs), thereby starting a new era for the refrigeration industry with ozone-friendly chemicals with low global warming potential, according to the Department of State.
The selection of refrigerants is critical, driven by factors such as environmental impact, energy efficiency, regulatory compliance, safety considerations, system compatibility, and cost implications. Choosing refrigerants that align with environmental safety standards is important, offering zero Ozone Depletion Potential (ODP) and low Global Warming Potential (GWP). Compliance with strict regulatory frameworks is necessary to mitigate environmental and safety risks.
Refrigerants must be compatible with existing refrigeration systems or require adjustments to accommodate new types. Safety remains a top priority, particularly in handling and operational protocols to prevent accidents due to some refrigerants’ flammable or toxic nature.
As the industry continues to evolve, the focus is on adopting refrigerants that reduce environmental impact, enhance system efficiency, and are cost-effective. The trend is moving away from HFCs towards sustainable alternatives like CO2 (R-744) and propane (R-290) that offer lower GWP and are becoming more prevalent due to their efficiency and lower operational costs. The future of commercial refrigeration leans heavily on innovations that prioritize sustainability and environmental responsibility.
CFCs, HCFCs, HCs, natural refrigerants, blends, and low-GWP alternatives are common refrigerants used in commercial refrigeration systems. Keep reading to learn about the details of these refrigerant types.
Chlorofluorocarbons (CFCs)
Chlorofluorocarbons (CFCs) are the first artificial and chlorin-based refrigerants. They were developed in the first half of the 20th century and became the dominant compound in the industry. However, after the discovery of their damage to the Ozone Layer and environment, these CFCs have been banned since the 1990s. However, there is still a large illegal market for these CFCs, such as R11, R12, and R115, since the refrigeration units and systems that use CFS have not been completely modified to work with new types of refrigerants.
Hydrochlorofluorocarbons (HCFCs)
Hydrochlorofluorocarbons (HCFCs) emerged in the 1980s when the CFS were started to be banned due to the ozone layer depletion. HCFCs such as R22, R123, and R124 contain less chlorine and, are considered to be less damaging for the Ozone Layer with lower Ozone Depletion potential. They gained significant popularity in the 1980s as an alternative to CFCs. HCFCs are still a threat to the environment and they are subject to a slow but decisive phase-out that aims to eliminate the use of these chemicals by 2030.
Hydrofluorocarbons (HFCs)
Hydrofluorocarbons (HFCs) are organic and synthetic chemicals that do not contain chlorine and, have zero Ozone Depletion Potential. Introduced first in the 1980s, HFCs such as R-134a, R410A, and R507A rapidly spread into the refrigeration industry with their nonflammable, nonreactive, and chemically stable nature. However, they have a high global warming potential, which is much higher than even carbon dioxide, and HFCs were added to the Kigali Amendment as one of the chemicals to phase down.
Hydrocarbons (HCs)
Hydrocarbons (HCs) are non-toxic and climate-friendly refrigerants with low global warming potential and zero Ozone Depletion potential. But they are quite flammable when not handled properly by experts. HCs such as Propane (R-290), Isobutane (R600a), and Propylene (R1270) are flammable. Some countries banned their use while the European Union allowed the use of household refrigeration equipment.
Natural Refrigerants
Natural refrigerants are compounds that can be found in nature to use as refrigerants in cooling systems. Ammonia, Carbon Dioxide, HydroCarbons, and water are the most common types of natural refrigerants, and they offer zero or near-zero Global Warming and Ozone Depletion Potential. They are available in abundance in nature (though they need to be produced industrially for large-scale applications) and present lower costs. These refrigerants bring higher efficiency operation to lower your cooling expenses. However, Ammonia and HydroCarbons are very flammable substances, especially when not dealt with properly, while CO2 requires much higher pressure and pressure-resistant components.
Blends and Low-GWP Alternatives
The quest for the best refrigerant still continues, and new alternatives emerge for business owners and families. Hybrid or cascade systems use two different refrigerants in the same cooling system, which aims to reduce the ODP and GWP through less substance use, thereby lowering the leakage risks. These systems allow the use of HFCs and HFOs as the primary cooling refrigerant, and the system can be completed with less piping to circulate ammonia and propane.
Or, the systems can be designed to run on a new type of low-GWP alternatives, such as Hydrofluoroolefins (HFOs), which have much shorter atmospheric lives and much lower GWP. They offer lower flammability, lower risk, and higher performance.
What are The Criteria for Refrigerant Selection?
The main criteria for refrigerant selection are environmental impact, energy efficiency, regulatory compliance, safety considerations, compatibility, and cost implications. We recommend that you make your selection after careful consideration of these conditions.
Environmental Impact
Refrigerants are closely linked with environmental safety. Choose refrigerants with zero Ozone Depletion Potential (ODP) to ensure you do not damage the Ozone Layer, which is crucial for life on Earth. Zero ODP does not mean the refrigerant is safe for the environment. Choosing refrigerants with zero or low Global Warming Potential will lower your environmental impact while ensuring your compliance with the regulations.
Energy Efficiency
Energy efficiency is crucial for environmental safety and sustainability and greatly contributes to profitability. Hydrofluoroolefins and hydrocarbons offer less operational cost with higher cooling efficiency, while natural refrigerants are much cheaper to obtain since they are readily available in nature.
Regulatory Compliance
The government and international agencies closely monitor and strictly regulate refrigerants to reduce climate crises, Ozone Layer Depletion, and Global Warming. You must comply with international and local regulations regarding your equipment to maintain your business and reduce your climatic impact.
Safety Considerations
Safety is a critical criterion in the selection of refrigerants. Consider factors such as flammability, toxicity, and operational pressure. Non-toxic and non-flammable refrigerants are highly harmful to the environment and Ozone Layer, in addition to the flammable low-GWP and zero-ODP natural refrigerants as the options for you.
Refrigerants vary in their safety profiles, so select one that minimizes risks based on the refrigeration system’s specific application and environment. Train your personnel on the possible cases after leakage from the cooling system while ensuring expert handling of the cooling components. Adopt newer techniques and refrigerants, such as HFOs, that have lower flammability.
System Compatibility
All refrigerants are chemicals, regardless of their natural or lab origin. They can only be used with properly designed components. For instance, some refrigerants have a corrosive impact on rubber hoses or can damage the internal parts of the condensers and evaporators. Use only the refrigerant specified by the manufacturer or modify your system or equipment with the right components to use a new type of refrigerant.
Cost Implications
Consider the total cost implications of the selected refrigerant, including initial purchase price, installation, maintenance, and potential retrofitting costs. While more expensive upfront, some refrigerants offer lower long-term operating costs due to higher efficiency and reduced environmental impact penalties.
The Future of Refrigerants Used in Commercial Refrigeration
The future for all industries worldwide prioritizes the use of sustainability, lower environmental impact, and higher efficiency, and refrigerants are no exception. Commercial refrigeration manufacturers are moving from HFCs (R-404 and R-134) to low-GWP and zero ODP refrigerants such as CO2 (R-744) and propane (R-290), while HFCs will be phased out gradually.
Conclusion
In conclusion, the evolution of refrigerants in commercial refrigeration has been marked by a constant pursuit of balance between effectiveness, safety, and environmental responsibility. From the early development of CFCs to the present-day exploration of low-GWP alternatives and natural refrigerants, the industry has undergone significant transformations driven by regulatory pressures and environmental awareness.
While CFCs and HCFCs once dominated the market, their detrimental impact on the ozone layer and contribution to global warming led to their phased-out. This prompted the rise of HFCs, which, although less harmful to the ozone layer, posed significant concerns due to their high global warming potential. The ongoing transition towards natural refrigerants, such as hydrocarbons and CO2, underscores the industry’s commitment to sustainability and reduced environmental impact.
The criteria for selecting refrigerants have expanded beyond mere functionality to encompass considerations of environmental impact, energy efficiency, regulatory compliance, safety, system compatibility, and cost implications. Businesses must navigate these factors to ensure both operational efficiency and environmental responsibility.
Looking ahead, the future of refrigerants in commercial refrigeration lies in the adoption of low-GWP alternatives and natural refrigerants, supported by advancements in technology and regulatory frameworks. By embracing sustainable practices and innovative solutions, the industry can continue to meet the demand for effective refrigeration while minimizing its ecological footprint.
