Tuesday, May 19, 2009


Refrigerants from air conditioners and refrigerators can harm the environment. The refrigerants in older systems can damage the ozone layer, reason why they were later often substituted by hydrofluorocarbons (HFCs). However, HFCs are harmful greenhouse gases - their global warming impact is many times that of carbon dioxide (see table below). Between 2001-2003, the rise in atmospheric concentrations of HFCs was 13-17% per year, according to the IPCC.

General Electric (GE) has just asked the Environmental Protection Agency (EPA) for approval to - for the first time in the U.S. - use a hydrocarbon refrigerant in household refrigerators. Hydrocarbons do little or no damage to the environment. If GE gains EPA approval, it plans to introduce HFC-free household refridgerators in 2010.
Global Warming Potential
(100 year basis, relative to CO2=1)
Ozone Depletion Potential (relative to R11=1)
R12 CFC (Chlorofluorocarbon)85001
R134a HFC (Hydrofluorocarbon)13000
R22 HCFC (Hydrochlorofluorocarbon)17000.05
R404a HFC (Hydrofluorocarbon)38000
R290 HC (Hydrocarbon)<30
source: Foster Refrigerator

So, while this GE-announcement is good news, it's sad that it has taken this long. Hydrocarbon refrigerants are already in widespread use in the rest of the world. Greenpeace helped develop the technology that uses hydrocarbon refrigerants back in the 1990s. The world's major manufacturers -- Whirlpool, Bosch, Haier, Panasonic, LG, Miele, Electrolux, Siemens -- have now produced some 300 million refrigerators that use hydrocarbon refrigerants.

It's time that we have effective legislation to facilitate the shift towards clean and safe products. I have often advocated feebates as a superior policy, compared to standards, carbon taxes or emission cap-and-trade schemes. Many support the introduction of feebates for appliances (see California's Climate Change Proposals). However, others suggest that outright prohibition of HFCs in refrigerators and air conditioners is more appropriate.

After 15 year Delay, Green Refrigerator to Arrive in U.S., sort of - Solveclimate Blog

GE Opening a Door to a Future of Cleaner Home Refrigeration - GE News Release

Greenfreeze - Greenpeace

Safeguarding the Ozone Layer and the Global Climate System Issues related to Hydrofluorocarbons and Perfluorocarbons, Summary for Policymakers - IPCC/TEAP (2005)
http://www.ipcc.ch/pdf/special-reports/sroc/sroc_ts.pdf (2.01 MB)

Hydrocarbons in refrigeration - Foster Refrigerator

Cool approach to driving - Sydney Morning Herald

California's Climate Change Proposals - by Sam Carana

The GE Press Release says that GE plans to include isobutane in a new GE Monogram® brand refrigerator. This refrigerator will also use cyclopentane, another hydrocarbon, as the insulation foam-blowing agent to replace commonly used HFC foam blowing agents. The Press Release concludes that the climate change benefits could be significant.

The IPCC report says: "Ammonia and those hydrocarbons (HCs) used as halocarbon substitutes have atmospheric lifetimes ranging from days to months, and the direct and indirect radiative forcings associated with their use as substitutes are very likely to have a negligible effect on global climate".

Apart from the HFCs that are used as coolants and as foam-blowing agents, we should also look at the various cleaning agents that are used by manufacturers. Some background is given in the IPCC paper mentioned in the article. Chlorofluorocarbons (CFCs), Halons and Hydrochlorofluorocarbons (HCFCs) are covered under the Montreal Protocol. This protocol was originally signed in 1987 to phase out such ozone depleting substances. Manufacturers turned to substitutes such as Hydrofluorocarbons (HFCs) and Perfluorocarbons (PFCs).

The problem is that these substitutes contribute to climate change. When the Kyoto Protocol was introduced in 1997, it did cover HFCs, but the US never ratified the Kyoto Protocol. PFCs are also covered in the Kyoto protocol, but Nitrogen Trifluoride (NF3) was used in such small quantities that it was not deemed necessary to include it. Semiconductor manufacturers turned to NF3 as a substitute for PFCs and it is widely used as a cleaning agent during manufacture of liquid crystal displays (LCDs) and thin-film solar panels.

There are alternatives to using NF3, such as using fluorine gas, as I mentioned in an earlier comment. I've often advocated feebates to facilitate shifting to better alternatives, but given that NF3 is some 17,000 times more potent than CO2 as a greenhouse gas, it makes sense to ban NF3 altogether.

The California Air Resources Board (CARB) has adopted rules forcing semiconductor makers to cut fluorinated gases such as sulfur hexafluoride and nitrogen trifluoride by more than half by 2012. These gases are among the most potent contributors to global warming, trapping heat in the atmosphere at 6,500 to 23,900 times the rate of carbon dioxide.

Regulators say other, less harmful gases can be used instead, at a small cost to semiconductor firms. CARB estimates the annual cost of compliance with the new rules at $37 million over 10 years; the brunt of that total would fall on 13 semiconductor companies that operate 16 plants currently not in compliance with the new emissions target. [Mercury News, 02/26/2009]

The EPA recently named the six greenhouse gases targeted under the Kyoto Protocol -- carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulfur hexafluoride (SF6) -- and concluded that they do endanger public health and welfare within the meaning of the Clean Air Act.

CFCs like Freon-12 (R-12 or CFC-12) are not mentioned, even though the IPCC as far back as 2001 said that CFC-12 had an even stronger radiative forcing effect than N2O. As discussed, CFCs are not targeted under the Kyoto Protocol since they were already banned under the Montreal Protocol, but this ban made manufacturers turn to instead use HFCs and PFCs as substitutes.

Meanwhile, Micronesia and Mauritius have initiated a proposal to expand the Montreal Protocol to phase down HFCs. Backed by the EPA finding, the Obama administration is seen as likely to support such moves.

1 comment:

  1. Many of the Commercial refrigeration today are manufactured using stainless steel materials because of ease of maintenance, not to mention that and they typically are consistent with other equipment in the commercial kitchen.