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DuPont and Honeywell to Partner on Low Global Warming Refrigerants for Automobiles

DuPont and Honeywell have entered a global joint development agreement to accelerate the development and commercialization of flourine-based, low global warming refrigerants for mobile air conditioning (MAC) systems in automobiles.

Today’s automotive air conditioners use hydrofluorocarbon (HFC)-134a—one of the basket of greenhouse gases monitored by the Kyoto Protocol. HFC-134a has a significantly larger global warming potential (GWP=1,300) than carbon dioxide (GWP=1). New regulations in Europe (the MAC Directive) phase out HFC 134a from 1 January 2011 onward for new vehicle models and from 1 January 2017 for all new vehicles. (Earlier post.)

DuPont and Honeywell will work together to identify, develop, test and qualify new low GWP refrigerants that could be cost-effective alternatives to other technologies currently being considered by the auto industry, which include CO2 as well as hydrocarbon (usually, propane and iso-butane) based systems.

Although HFC-134a in itself has a significantly higher GWP than CO2, automakers are also looking to understand the impact of the entire MAC system in the context of the vehicle and different operating conditions. The tool used for this is the Total Environmental Warming Impact (TEWI) analysis. TEWI takes into account the contributions to global warming of:

  • The overall efficiency of the air-conditioning system which directly affects fuel burned to power the system and thereby, the carbon dioxide from that related combustion;

  • The emission of CO2 from burning fuel to transport the (mass of the) air-conditioning system; and

  • The result of refrigerant being released to the atmosphere due to leakage, servicing and accidents.

A TEWI analysis by GM and Oak Ridge National Laboratory of HFC-134a and CO2 systems in different vehicles operating in different cities found that while CO2 systems can offer better TEWI performance in cooler regions, HFC-134a systems offered better TEWI performance in warmer regions. As an example of a contributing factor, the increase in compressor power consumption required in a CO2 MAC solution deteriorates fuel consumption.

DuPont and Honeywell are thus trying to develop a refrigerant with a lower GWP than 134a that is compatible with the conventional HFC-134a mobile air conditioning system technology and offers a more cost-effective industry transition versus CO2 technology.

We look forward to providing a near drop-in replacement that reduces the need for costly system redesign for the automotive industry. For the consumer, we will provide an environmentally friendlier, low-GWP solution without sacrificing comfort or reliability.

—Terrence Hahn, vice president and general manager for Honeywell’s Fluorine Products business

In November 2006, DuPont Refrigerants demonstrated DP-1, a new, low GWP refrigerant. DP-1 is a two-component blend, the major component of which is a new non-flammable, fluorine-based compound. The minor component is a commercially available refrigerant. The refrigerant ran in an unmodified MAC system.

According to DuPont, DP-1 offers properties and performance similar to that of R134a while featuring zero ODP (Ozone Depletion Potential) and a very low GWP estimated at 40. (Earlier post.)

DuPont and Honeywell plan to share resources, investment and technology as part of the agreement. The companies will work closely with the automotive industry to qualify a low GWP alternative by mid-2007.

According to industry estimates, there are more than 400 million cars with air conditioning systems globally, with each system using between one to two pounds of refrigerant. Based on a test conducted by DuPont comparing mobile AC systems utilizing DuPont’s low GWP replacement refrigerant and CO2, widespread utilization of a fluorine-based refrigerant could lead to worldwide emissions reduction equivalent to 230 million gallons of fuel per year by 2017.




Is this bringing a toy water gun to a burning building? That toy water gun will help put out the fire, but it won't help much.

I ask because of the quote "HFC-134a has a significantly larger global warming potential (GWP=1,300) than carbon dioxide (GWP=1)". The question I have is: what is the total GWP impact of the lifetime operation of a 2008 model year auto due to carbon dioxide, and what is the total GWP impact due to air conditioning? I suspect that the carbon dioxide emissions have orders of magnitude more impact, but that's based on a hunch, not on science.

Any data?


I've been using propane/isobutane as a refrigerant in my car's AC system for the past two years now. Works great. I have measured the high side pressure and it is half that of what R-134 would give. And in Canada, you don't need a license for charging, which you do if you use R-134.

I don't think that Dupont would have any interest in propane/isobutane, as there is already a well established market for this refrigerant mixture, and they cannot patent it. Reminds me of GM back in the twenties, when they were experimenting with anti-knock additives. They thought of using ethanol, but instead went with highly toxic tetraethyllead, because they could get a patent on it!


Although you're right about the total impact HFC-134a has compared to CO2, Honeywell et all do not manufacture cars, and therefore their contribution is the weening out of this old refrigerant. Every little bit helps.

Paul Dietz

They thought of using ethanol, but instead went with highly toxic tetraethyllead, because they could get a patent on it!

Surely that it ended up being cheaper was also relevant?

Stan Peterson


A true blooded anti-capitalist to the very end. It was all a capitalist plot by GM as far back as the 1920's. Its ALWAYS a conspiracy. Gee, conspiracies everywhere, in the walls, under the bed, in the closet, under the floor. How do you dare get out of bed in the morning, or is the tinfoil hat sufficient protection?

Really, do you conspiracy people ever get together to review how stupid you all sound?


Stan - I wouldn't quite but miket's comment on the level of conspiracy theory. You obviously have never worked in a tech company. The ability to patent aspects of a product plays a role in what gets sent to market. If you have no patent protection, anyone can copy your product and erode any market advantages you may possess. That's what differentiates a valuable product from a commodity. Where's the margin in a commodity? DuPont is not interested in commodity products hence their shedding of many older product lines.

Stop pretending to know something when you don't.


Stormy, Richard,
While its true over the lifetime of an average vehicle (15-20 years, 150K-200K mi), the effects from CO2 emissions dwarf the released/leaked refrigerant's, these chemicals take thousands of years to break down. Hence, their GH effect continue long after the CO2 may have been absorbed/converted/sequestered. Factor in a billion or two new drivers and home/work AC users, in the next half century and you get the picture.


I found the Alternative Refrigerant Assessment a bit disappointing in how the data was presented. Reading the graphs for Phoenix, the TEWI (Total Environmental Warming Impact) for CO2 based A/C in a "typical" car is 45% higher than R134a A/C, propane A/C is about 25% higher. The position of the Japanese seems pretty clear, forget about CO2 A/C please!
If Honeywell/DuPont can really develop a more efficient, green, drop-in replacement for R134a, more power to them.



Give me a break! Anti-capitalist! Conspiracy theories? It's amazing what a person can read into another's comments. I am a firm believer in being able to patent an invention. I happen to have my name on several patents related to synthetic organic chemistry. Too bad that I never made money off of them.

Read R's comments. I agree completely with what he wrote.



You probably want to read this:

It explains a lot. Anger and frustration do not help (also applies to me).

As for patents, they expire at about 18 years after patent application date. After that everybody can use patented technology for free.

joseph padula

GM did not have the patent on lead in gas, dupont did.

joseph padula

When they first started making lead compounds for gas octane boosters, so many people died in the NJ refineries (Dupont), it was made illegal to us for several years by US government. Lobbing overcame the objections since compression ratios could be increased and fuel consumption fell.
In UK, the Oil companies used ethanol to boost octane instead, but claimed it would not work in US.
GM was convicted in Chicago, along with standard oil, firestone, phillips petroleum, on march 12. 1949 of conspiracy to monopolize transit businesses. It was appealed to Spream court and upheld. They bought up a little less than 100 trolley lines(includin LA) and burned them and replaced them with GM busses, firestone tires etc.
Look it up don't take my word for it.

Steven Reiser


Just a comment in regard to HFC-134a vs. CO2. If a driver drive their car 12,000 miles per year for 15 years and the car gets 20 miles per gallon, during the life of the car they will put about 19 tons of carbon dioxide into the air. If their air conditioner leaked refrigerant bad enough that it required an annual recharge with 2 pounds of refrigerant, the effect of the 30 pounds of refrigerant over the life of the automobile would be the same as the total effect of all the gasoline.

I personally have a 17 year old Mustang GT 5.0 that gets 25 miles per gallon on the highway but has only had the air conditioner recharged a couple of times in the time I've owned it purchased new. Hence in my case, the effect of the car exhaust will far outweigh the refrigerant.

I am also a Chemical Engineer/Chemist and worked in the oil and natural gas industries 25 years ago and thought I would put some simple calculations behind the questions posed above.




Could you please provide links to the documents?

Just curious, how executives of transparent public traded companies – four major oil, tire, and automotive giants – risked their asses and fat paychecks to commit broadband illegal conspiracy for peanut profits for their shareholders. And how windy Chicago court managed to investigate purchases in sunny California.


>GM did not have the patent on lead in gas, dupont did<

One in the same ... DuPont owned (literally) GM during that period ... DuPont was forced to divest their ownership of GM after WWII because of government anti-trust pressure.

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