The current trend in automotive refrigerants can be summed up as this: everything's new and nothing's new.

The automotive industry is gearing up for a replacement for the environmentally unfriendly R-134a, but no new alternative formulas have been created since last year when we reported on this chemical category.

The frontrunner for replacing R-134a refrigerant appears to be HFO-1234yf, a single-component refrigerant with a much lower global warming potential (GWP) than R-134a.

The Environmental Protection Agency has yet to set a timetable on replacing the current industry standard refrigerant, but "the new Democratic administration has asked for a very immediate and thorough review of ways that we can reduce our carbon emissions, particularly through automotive and industrial areas," says Peter Coll, refrigerant analysis product manager for Neutronics, which makes refrigerant identifiers and detectors. "So, although no timetable has been put together, we think it's not long before one is put together.
"I think what you may see is some reduction in purchase of equipment related to R-134a, (but) not a significant reduction because R-134a will be around for a long time," he adds.

Unfortunately, automakers have yet to commit to any new technology due to broader economic concerns. But a switch to a greener refrigerant is inevitable; it's only a matter of when.

"You're dealing with tremendous economic problems. I think it's going to give people a bit of an excuse to slow things down," says Jay Kestenbaum, senior vice president, product management for Airgas Refrigerants, Inc. "Incomes are down, profits are down, so how fast can you push someone to make a change. You're looking at a product that will be 10 to 15 times the multiple of R-134a. It's a big price difference."

The U.S. can afford to wait for R-134a's replacement, and "some estimate it will take longer than anticipated to implement HFO-1234yf," Kestenbaum says. However, for Europe the clock is ticking. Following the F-Gas Directive on Mobile Air Conditioning, which mandates that 2011 model-year vehicles need to have a refrigerant with a lower GWP than 150, automakers are scrambling to find an alternative technology that meets EU mandates.

R-134a has a GWP of 1,300. In comparison, HFO-1234yf has a GWP of 4.

And R-134a's price could increase as much as 10 to 15 percent due to shortages caused by, among other things, hurricanes in Mexico, which affect the supply, Kestenbaum says.

DuPont has issued a 14-day lead time on R-134a due to supply interruptions.

Concerns with many alternative refrigerants introduced over the past couple of years have included flammability and infrastructure.

As far as the flammability issue, "As we know, car manufacturers are extremely careful about that to the best of their abilities to make sure things are contained properly," says Coll. "There will be some new regulations related to it. You well may not be able to buy HFO-1234yf at your local Wal-Mart like you can with R-134a. There will be new training and new certifications required, but as a substance itself, I would view it as a very low risk on the flammability scale."

An HFO-1234yf system would require only minor modifications from what we use today. From a technician's standpoint, what they know about R-134a systems could translate directly over to an HFO-1234yf system, Coll adds. Additionally, leak detection systems would be similar save for some software updates.

Regardless, any changeover will require new refrigerant recovery equipment. The refrigerant recovery/recycling/recharging equipment will be very similar to what currently exists for R-134a, but techs would need an independent machine to handle that. HFO-1234yf can be recovered, recycled and recharged on site because it is a single component product.

Another option explored by experts in the industry is CO2, also known as R-744, which has a Global Warming Potential (GWP) of 1. CO2 has been in consideration for a number of years, and may even be a transitional technology.

Coll says only part or very little of what techs know about today's system would be transportable to a CO2 system.

"CO2 would be a better option in cooler climates like Germany," says Elvis Hoffpauir, president of the Mobile Air Conditioning Society (MACS). "If you look at places where there's heat, CO2 does not lend itself to those conditions."

Many say that CO2 also has flammability concerns, but the real issue is the high pressure involved in CO2 systems, says Coll.

Also, to develop CO2 into a usable refrigerant would involve adding an odorant to the mix so drivers would be able to quickly detect a leak into the vehicle's cockpit.

"You don't want that passenger compartment to have a reduced oxygen level replaced by CO2," says Coll. "You'd get that rotten egg smell first and you would know something was wrong."