For What It’s Worth

Remember when Congress banned freon to save us from the ozone hole? Turns out the replacement causes global warming [sic] so the switch is on again. result: still worse performance, still more expense and, naturally, yet another product to be banned in a few years when scientists discover what’s wrong with this one.

Here’s Popular Mechanic’s take on the subject. I can’t follow much of it, but the conclusion is obvious enough.

Fifteen years ago, the auto industry was forced to drop CFC-based refrigerant R-12 because of its liability for ozone depletion. They switched to non-CFC-based R-134a, which, as it turned out, also provided a substantial reduction in greenhouse gas liability. How much better is R-134a? Carbon dioxide has a global warming rating of 1. R-12 has a rating of 12,000. In other words, one pound of R-12 has the equivalent effect on global warming as 6 tons—12,000 pounds—of CO2. Years ago, that made R-134a’s rating of 1400 seem like a better deal. (As a point of reference, it takes one or two pounds of CO2 to dispense an entire keg of beer). But now automakers are considering a new refrigerant for worldwide use— R-1234yf. This new refrigerant has a global-warming impact number of just 4.

There is no intent to retrofit R-134a systems with the new R-1234yf, in the way many R-12 systems were haphazardly converted to R-134a. R-134a will remain available to service existing systems, and R-1234yf systems will use specific fittings, which should minimize accidental mixing of the two refrigerants. R-1234yf is slightly less efficient than R-134a. Of course, R-134a is less efficient than R-12, and auto manufacturers had to modify and upgrade systems to maintain good cooling performance when the last changeover was mandated. They’ll need to do so again.

R-1234yf will first appear in all-new European vehicles, so we might see some R-1234yf systems here by late 2011, with significant numbers starting in 2012.

Although R-134a continues to be available in small cans to DIYers, California will soon require self-sealing can valves and large deposit fees to encourage recycling of any leftover refrigerant in partially used cans. Whether R-1234yf will also be available in small cans is uncertain. Pro technicians are legally required to recover, recycle and reuse all auto a/c refrigerants. And that means that repair shops will have to purchase yet another expensive recycling machine for R-1234yf and inventory a larger collection of fittings and replacement parts, costs ultimately passed on to consumers.