Combating Climate Change Through HFC Mitigation

UC Berkeley, CE 105

May 2022

Before we delve into the details of HFCs and our project, here is a visualization to better understand the magnitude and importance of this global warming crisis.

HFCs can have extremely high global warming potentials (GWPs). A high  GWP  means that for any amount of given mass, HFCs absorb and trap thousands of times more heat than carbon dioxide. The higher the GWP, the more that gas warms the Earth compared to carbon dioxide, over a 100-year time period.

When HFCs are emitted, they create a blanket over the atmosphere. When the sun radiates heat onto the Earth, this blanket traps the heat. This causes temperatures on Earth to increase. HFCs are only  1% * of global GHG emissions, but can have global warming contributions thousands of times greater than carbon dioxide.

*This value is underreported due to lack of HFC data available. Based on the calculations from available data, HFCs make up over 2% of GHG emissions in California

One of the most used refrigerants in commercial refrigeration systems is R-404A. It has a  GWP of 3,992  and is commonly found in supermarkets like Walmart and Safeway. According to the  EPA :

One pound of R-404A emissions is equivalent to burning 1,968 pounds of coal. Meanwhile, one pound of carbon dioxide emissions is equivalent to burning 0.502 pounds of coal.

The use of R-404A alone contributes significantly to rising Earth temperatures.

For this reason, alternatives to high GWP refrigerants like R-404A are key to combating global warming and stopping the greenhouse effect.

Left unchanged, the positive feedback loop will continue. See how below...

The  California Air Resources Board  (CARB) has a Refrigerant Management Program where stationary non-residential facilities that use more than 50 pounds of a high GWP refrigerant are required to  report  to. Our team  compiled the data  and found that in 2021, over 850,000 metric tonnes of carbon dioxide equivalent (MTCO2e) was emitted from R-404A leakage. According to the  EPA : 850,000 MTCO2e is equivalent to greenhouse gas emissions from burning 940,000,000 pounds of coal or 95 million gallons of gasoline being consumed. This estimate does not include HFC leakage from residential use; thus, this estimate is expected to be considerably underreporting HFC emissions from refrigerant leaks.

To find better alternatives to R-404A, we researched the non-residential refrigerants R-448A, R-450A, and R-513A.

Toxicity & flammability ratings range from A-B for toxicity (A being the least toxic and B being the most) and 1-3 for flammability (1 being least flammable and 3 being the most).

As mentioned previously, over 850,000 MTCO2e were emitted from R-404A leakage in stationary non-residential facilities in California in 2021. A switch to lower warming potential refrigerants would decrease the amount of MTCO2e from leakage.

MTCO2e impact would decrease by 64%, 84%, and 85% if R-404A was replaced with R-448A, R-513A, and R-450A, respectively.

It is important to note that the amount of emissions from leaks will NOT decrease, but rather the impact on global warming would decrease because the proposed refrigerants have significantly lower warming potential. 

The  Kigali Amendment  aims to globally phase out HFCs by cutting their production and consumption and has been ratified by 129 countries. While the United States has not ratified the amendment, the Senate is expected to ratify it soon. Global efforts like this are pivotal to combating global warming because it is  estimated  that:

"A global HFC phasedown is expected to avoid up to 0.5° Celsius of global warming by 2100."

In December 2020 the United States enacted the  American Innovation and Manufacturing Act  which aims to achieve very similar goals to the Kigali Amendment. This act required the EPA to put forward an implementation plan which would reduce production and consumption of HFCs by 85% over a 15 year period.

The state of California has a  Climate Change Scoping Plan  that aims to reduce GHG emissions by 40% below 1990 levels by 2030. In 2020 CARB proposed  regulations  on refrigerants to achieve this goal, outlined below. However, these regulations continue to be  modified and delayed  since.

The California Air Resources Board estimated how the Kigali Amendment alone would impact HFC emissions in California, shown in the figure below.

Stockton has a history of bad air quality, and the leakage of high GWP refrigerants will only exacerbate the air quality; thus the phase out of high GWP refrigerants in Stockton is crucial. The EPA has already set forth an implementation plan for the legislation described in the previous section, however there are existing programs that help facilities comply with the new refrigerant regulations that Stockton facilities can apply to.

For example, the  F-Gas Reduction Incentive Program  provides funding for facilities to transition to climate-friendly refrigerants. This program is likely to receive about $30 million with new changes to the  Climate Change Scoping Plan .

This project could not have been possible without Kristen Taddonio, who served as an advisor and expert on the topic; CARB’s HFC database, which provided the estimates used in our calculations and visuals; and Professor Chow, Jennifer Hoody, and the CE 105 teaching staff and students for their guidance.