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WARREN, MI — General Motors plans to use a new air conditioning refrigerant for its 2013 models that is a less potent greenhouse gas than the current common refrigerant.
The primary vehicle refrigerant in use is HFC-134a, which is some 1,400 times more potent than carbon dioxide (CO2) when it comes to global warming and is being banned by the European Union.
While HFC-134a stays in the atmosphere for more than 13 years, the new refrigerant, HFO-1234yf, has an 11-day atmospheric life and a global warming potential (GWP) of 4. The baseline for GWP is CO2, which has a GWP of 1.
GM will source HFO-1234yf for its 2013 Chevrolet, Buick, GMC and Cadillac models from Honeywell, which is producing the refrigerant in cooperation with DuPont. The two companies entered a joint venture earlier this year to build a large-scale manufacturing plant for the refrigerant, but sell it separately.
The companies introduced the refrigerant in 2007 and are working to produce a larger supply of it in advance of the European Union ban on HFC-134a that begins next year.
Advocates for the use of non-synthetic refrigerants like CO2, ammonia and hydrocarbons like propane and butane are opposed to the introduction of HFO-1234yf, saying that it can pose dangers if accidentally vented into the vehicle or if a car crashes.
Although the new refrigerant is mildly flammable (HFC-134a and CO2 are not flammable), an SAE International Cooperative Research Program found that the chemical is safe for use in automobiles that are designed to use it.
In Europe, a wholesale switch to HFO-1234yf seems inevitable, as Chemical & Engineering News reports that the German Association of the Automotive Industry has put its weight behind the new refrigerant even though in 2007 it stated it would switch to using CO2 for vehicle air conditioning. Moving to CO2 would require new equipment for automakers, while going from HFC-134a to HFO-1234yf would provide less hassle.
Air conditioning controls - CC license by Flickr user Dan Bock
It's great news that anything
It's great news that anything is being done to reduce HFC emissions, but it's worth noting that hydrocarbon refrigerants (blends of propane R290 and isobutane R600a) are in very wide use in North America, and are a readily available solution for servicing existing systems. They are safely and reliably used in many countries worldwide, and addressing the current lack of regulatory approval of HCs in the USA could make a vastly greater reduction in emissions than many years of new production of low GWP AC vehicles.
The science on the environmental acceptability of HFOs is far from certain, and many serious questions of concern are waiting to be answered. We should be very cautious about endorsing a new fluoro-chemical when natural refrigerant solutions such as hydrocarbons and CO2 are available, as developments in the science expected next year may well pose fresh challenges for R-1234yf. Significant concerns also exist about the toxicity of R1234yf, especially when exposed to heat.
Hydrocarbons have significant cost advantages, and over nearly two decades have been proven to be safe, efficient and environmentally acceptable solutions to the very large high Global Warming Potential HFC problem, perhaps it is time for a re-evaulation of the suitability of hydrocarbons in new systems?
As much as the fluorochemical lobby may not like it (and they can be relied upon to campaign against the use of hydrocarbons in any application), surely the emissions abatement and performance and cost benefits available from the rapid roll out of hydrocarbon technologies will be worth the effort?