Observer: 'Miracle blend' refrigerants face chilly end

DP-1 is dead. For the uninitiated, DP-1 was one of a few "miracle blend" refrigerants rolled out last year, on which high hopes were placed to save our industry. But they just didn't work, and the companies involved with these refrigerant blends have kept quiet as to what went wrong.

"What happened was, all those blends that Honeywell and DuPont and other companies were working on for one reason or another did not pass muster," says Paul DeGuiseppe, manager of service training for the Mobile Air Conditioning Society (MACS).

The auto industry, especially overseas, is looking to cut its usage of the environmentally unfriendly R-134a yet find a replacement that will efficiently operate in a vehicle's air conditioning system throughout myriad external conditions.

R-134a, our mainstay refrigerant, is living on borrowed time, because of its high Global Warming Potential (GWP).

How does all this affect the aftermarket? To replace R-134a will likely involve an overhaul to the current infrastructure of shop A/C recovery machines, not to mention retooling cooling-related auto parts.

The U.S. Environmental Protection Agency recently issued a ruling approving the use of R-152a as an alternative, but it is mildly flammable.

The agency is requiring a label be placed on the systems noting the refrigerant's flammability. R-152a has a GWP of 130. In comparison, R-134a has a GWP of 1,300.

Automakers also are currently banking on CO2 (also known as R-744) and its attendant benefits and downfalls.

Behr Hella Service is preparing CO2 ready systems, but officials are clear that they will follow the lead of the automakers, most of which have not made formal commitments to a refrigerant technology.

"We've been testing (R-744) for 14 years now, getting it ready for production," says John Tepas, chief engineer, HVAC North America, for Behr Hella Service. He says CO2 has an eight-minute faster cooldown than current refrigerants in use. "And it's the only option that's out there that has literally the absolute minimum global warming potential." CO2 has a GWP of 1.

Using CO2 in a car would likely decrease fuel efficiency due to the extra load it would place on the engine, DeGuiseppe says. "A lot of the components will need to be heavier." CO2 is highly pressurized and the components involved will have to be thicker to protect driver and vehicle.

CO2 also runs into efficiency problems at high temperatures, admits Tepas, who adds this problem can be mitigated through redesign of front-end modules.

HFO-1234yf, another alternative being explored, is a single component taken from one of the aforementioned "blends" that were touted last year, but this substance also is flammable.

"Delphi is developing options that meet the new regulations, including the DuPont/Honeywell proposed HFO-1234yf that could replace R-134a as the refrigerant used in automotive air conditioning systems compliant with the EU legislation," says Frank Ordoñez, president of Delphi Product & Service Solutions, who adds that HFO-1234yf has a GWP of 4. He is speaking of the F-Gas Directive on Mobile Air Conditioning that mandates 2011 model-year vehicles have refrigerant with a GWP lower than 150.

"In addition to this option, Delphi has developed systems that use R-152a in a secondary loop arrangement, which is being considered by some automakers as a back-up option for compliance," Ordoñez adds.

But none of the current choices are "drop-in" refrigerants, which means they can't be used with current automotive cooling components and shop equipment.

— Chris Miller