Refrigerants are substances that are common in air conditioners, HVAC, refrigerators, and freezers. The natural ones are water, ammonia, carbon dioxide, and natural hydrocarbons. They have the potential to become alternatives to synthetic refrigerants like hydrofluorocarbon (HFC), hydrochlorofluorocarbon (HCFC), and chlorofluorocarbon (CFC).
Many companies are concerned with the environmental impacts of synthetic refrigerants, and they found that organic ones are more sustainable in nature. With the current technologies developing today, many believe that the air conditioning sector will switch and convert into natural refrigerants for more eco-friendly systems. This is a must today since the use of HVAC systems is prevalent around the world.
A Background about Refrigerants
Synthetic coolants like HCFCs and CFCs have been around since 1929, and they were used in various ACs and fridges to cool a specific area. However, when they leak out of the older systems, they go to the atmosphere, and they thin out the ozone layer. Hence, they contribute largely to the global warming that everyone feels today.
CFC contains fluorine, carbon, and fluorine. For years, it has contributed significantly to the amount of inorganic chlorine in the earth’s stratosphere, where they are decomposed by ultraviolet radiation. The released chlorine in the environment is becoming active when it comes to the destruction of the ozone layer and the melting of the polar ice caps.
The HCFCs generally have a shorter lifetime while in the atmosphere because there’s added hydrogen in the mix. However, they still contribute to the adverse effects of chlorine elements with their CFC counterparts. The HFC, meanwhile, may not contain any chlorine, but their abilities to absorb the infrared radiation can become a contribution of the greenhouse effect. Learn more about HFC on this site here.
In the year 1987, it’s the Montreal Protocol that had first acknowledged and banned the use of CFCs. Many homeowners are encouraged to get newer appliances, and manufacturers are searching for other ways to give them a coolant that won’t harm the environment.
Many of the brands before are now phased out because amendments are being in place to eliminate HCFCs by 2020 and CFC production in 2010. On the other hand, the negligible impacts of HFC on the ozone layer made them viable candidates and ideal as a replacement. However, know that these too have implications in the world’s global warming, and there are calls for amendments that the use should be cut back by around 80% for the next three decades.
Potential options, as mentioned, were carbon dioxide, water, and other refrigerants as a replacement for HFCs. This industry is growing, and it’s expected that it will become a billion-dollar niche in 2027.
Metrics of Sustainability
The refrigerants are typically measured with their potential in contributing to ozone depletion and global warming. The global warming potential scales or GWP is standardizing the carbon dioxides. The value of a specific refrigerant is multiplied by the heat it would absorb by the same mass of CO2 gases in a given amount of time. The period is usually measured in a century.
It was found out that CFC has over 10,900 potential in global warming while ethane only has 6. You can view the results of HFC, water, and ammonia on many websites that offer these pieces of information in detail.
About the Hydrocarbons
Pure hydrogen compounds are now being moderately used in refrigeration systems. Know that these hydrocarbons are viable options. This is because aside from providing cooling properties, they are efficient in energy use and plentiful. When harnessed and used correctly, it was found out that they have more than 50% energy efficiency compared to synthetic ones. They are very environmentally friendly, and they have lower ranks on the GWP scale.
In the past, the hydrocarbons were primarily seen as a refrigerant in an industrial-scale of cooling. Know more about hydrocarbons on this site: https://www.sciencedirect.com/topics/chemical-engineering/hydrocarbon. However, with the current trends today, many start to look for a more environmentally friendly option in the residential setting.
Some of the hydrocarbons used in many refrigerants include ethylene, methane, propane, pentane, isobutane, and cyclopentane. One of the primary disadvantages of using hydrocarbons is their high flammability. They can cause fire when exposed to extremely high pressures. Before, this same risk was mitigated by turning the hydrocarbons into other forms like HFC and CFC. Still, with the companies decreasing the use of such substances, being too flammable should be fixed.
Today, the use of hydrocarbons as refrigerants is under EPA guidelines. Particular pressurized levels are limited when it comes to hydrocarbons. The level of caution is essential, and for the hydrocarbons to combust, they should be mixed with a correct air proportion. The EPA has guidelines that prevent hydrocarbons from causing sparks and ensure the highest levels of safety for companies and consumers.