Refrigerants play a vital role in our lives. They keep us cool, prevent food from spoiling, maintain the potency of vaccines and insulin, and so much more. Unfortunately, refrigerators and air conditioners use a lot of energy and contain harmful chemicals, so the cooling industry has a huge impact on the environment. As the world’s population continues to grow and temperatures rise, the challenge is in meeting surging cooling demands sustainably without creating new problems. Governments and companies around the world have pledged to crack down on climate-warming chemicals. Consumers can play their part as well.
A Brief Timeline of Refrigerants
Chlorofluorocarbons (CFCs)
Remember when shaving cream cans created a hole in the ozone over the Antarctic? That was because the aerosol propellants contained a specific class of chlorine containing chemicals known as chlorofluorocarbons (CFCs). These CFCs were also in refrigerants* for refrigerators and air conditioners (RAC), and while they were not harmful during the working life of these appliances, once they were disposed to landfill or junkyards and started to rust, the refrigerants leaked out, went up into the stratosphere, and destroyed ozone molecules, reducing the ozone layer’s capacity to shield earth from lethal levels of ultraviolet sunlight.
Luckily, CFCs were phased out after the landmark 1987 Montreal Protocol, arguable the most effective international environmental agreement ever written. With all 200 U.N. nations signing on, 90% of the world has rejected CFCs, and the ozone layer is expected to fully heal by 2060. But CFCs were replaced with chemicals with a different problem.
Hydrofluorocarbons (HFCs)
DuPont’s Freon (which was banned in 2020) was a standard CFC used in older residential and commercial refrigerators and air conditioners (RACs), but even before the Clean Air Act passed in 1990 industries were already creating “substitute refrigerants” called hydrofluorocarbons (HFCs). The addition of hydrogen allowed refrigerants to break down in the atmosphere more easily than the chlorine in CFCs did, so HFCs were touted as being safe for the ozone. But HFCs are hardly environmental. Although HFCs don’t deplete the ozone and may be safer than CFCs in that regard, their molecular structure allows them to readily absorb thermal radiation. Instead of escaping back into space, this heat gets trapped inside the atmosphere and creates a greenhouse effect. In fact, the global warming potential (GWP)** of HFCs is actually hundreds to thousands of times greater than carbon dioxide! For example, after 100 years, one type of HFC has a GWP of 12,400, compared to just 1 for CO2. (Source: Wikipedia).
“Hydrofluorocarbons are the worst greenhouse gas that nobody's heard of,” says Danielle Wright, executive director of the environmental nonprofit the North American Sustainable Refrigeration Council. Researchers at Project Drawdown, a nonprofit that focuses on cutting greenhouse gases, puts management and disposal of HFC refrigerants at the very top of the list of global climate impact solutions.
Next Generation Refrigerants
Most new air conditioners contain a safer refrigerant called R-410A, also called Puron, which was approved by the EPA and considered a long-term solution, but even Puron is an HFC and will be banned in 2024. A next generation refrigerant called R-32 will phase out R-410A because it has one-third the global warming potential, but it too is an HFC and unsustainable. The perfect combination of planet-friendly traits seems elusive. As Wikipedia states: “The ideal refrigerant is non-corrosive, non-toxic, non-flammable, and does not deplete the ozone or have global warming potential. “
What Is Being Done Globally?
In response to the threat posed by HFCs, the Kigali Amendment was added to the Montreal Protocol in 2016 to mandate a global phasedown of the consumption and production of HFCs to the tune of 80% over the next 30 years. President Biden issued an executive order asking Congress to ratify the amendment, and the United States (as well as China) has pledged to do so. The goal is to prevent a 0.5 degree Celsius rise in global warming by 2100, which would help reach the goals of the Paris Agreement.
The Importance of Containment and Disposal
If synthetic refrigerant gases were contained and disposed of properly at the end of their usable life, the high global warming potential may not become a major concern. The EPA has established several rules for the proper handling and disposal of refrigerants. Refrigerants must not be intentionally vented (for servicing, connecting, disconnecting); technicians must capture, recycle, and dispose of them safely and according to EPA rules; leaks must be repaired within 30 days; only licensed heating, ventilation, and air conditioning (HVAC) companies can purchase refrigerants; and violation of these regulations can incur harsh penalties. (Source: https://www.ccacoalition.org/en/slcps/hydrofluorocarbons-hfcs).
Despite these regulations, emissions of synthetic refrigerants, whether they are CFCs, HFCs, or HCFCs, inevitably occur as a result of equipment deterioration, venting while servicing, faulty maintenance, or leakage at the end of a product’s life. The Environmental Protection Agency estimates that all supermarkets in the U.S. leak an average of 25% of their refrigerants annually.” According to Climatefriendlysupermarkets.org., the average U.S. supermarket leaks roughly 875 lbs. of HFCs a year, which is equivalent to the emissions of 336 additional cars on the road. To see how your grocery stacks up, learn more about leaks, and discover which stores pledge to be climate-friendly, go HERE and HERE. You can see what type of refrigerant is in your own, current refrigerator by checking the label inside. HERE is a guide for buying an HFC-free fridge. If you want to learn more about whether your home’s air conditioning system will need to be replaced, go HERE.
Natural Refrigerants
There is a growing trend towards using refrigerants that exist naturally in the environment. A natural refrigerant system has a GWP of less than 10 (typically 1 or 3), whereas HFCs have GWPs in the thousands. With zero ozone depletion potential (ODP) and low global warming potential (GWP), natural refrigerants are considered a solution to the damage caused by synthetic refrigerants and include carbon dioxide, hydrocarbons, ammonia, water, and even air. According to Greenpeace, natural refrigerants also outperform HFCs from an economic standpoint. Although there are additional expenses incurred when companies install new natural refrigerant systems, operational costs are lower in the long run because of lower leakage related costs, the low cost of maintenance, and low energy consumption.
Although it seems counter-intuitive, carbon dioxide may turn out to be the best refrigerant of the bunch. Increasing rapidly in Europe, CO2 is plentiful, inexpensive, and the EPA puts it in the least toxic and hazardous category of refrigerants. Go here to see pros and cons of CO2. Hydrocarbon refrigerants such as methane and propane are ubiquitous and favored by many European countries, but they require extra caution due to their flammability. For an overview of natural refrigerants, visit HERE.
All natural and synthetic refrigerant options have their pros and cons in terms of reliability, convenience, safety, cost, availability, corrosive resistance, flammability, and leak-proof ability. Other industry solutions include reducing over-reliance on air conditioning in the first place by improving building insulation, increasing energy efficiency, and enforcing stricter standards.
*Refrigerants are compounds that change back and forth easily between liquid and gas states. They work by absorbing heat and leaving cool air behind after cycling through a system of condensors, compressors, and evaporators.
** Global Warming Potential (GWP): The GWP of a gas refers to the total contribution to global warming resulting from the emission of one unit of that gas relative to one unit of the reference gas, carbon dioxide, which is assigned a value of 1. Thus, it provides a common scale for measuring the climate effects of different gases. Gases with a higher GWP absorb more energy and contribute more to warming the earth.
Sources for this article include:
Photo by Eduardo Soares on Unsplash
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