R-12 & HFC's in general ?

Ken_40

Although this should be down below, where specific questions regarding A/C are supposed to be posted, there is enough "grist" here for the Wall to comment IMHO.

Here's the controversial link:

http://www.hotrodhotline.com/feature/tech/04hc12a/

Not knowing enough to comment intelligently, I would love to see those who work with A/C to read and comment for all our benefit.

Thanks

Ken D.

R12 and 134a

Whew. Makes you wonder. Propane and butane were widely used refrigerants before the 1940's. Refrigerators, freezers, etc. Methyl chloride, ammonia, and other exotic stuff was used also. Propane and butane are flammable and although those old systems were not hermetics, fires were not unheard of. Methyl chloride and others are toxic and ammonia is corrosive and can be dangerous. (Try breathing from your household bottle). I knew many an oldtimer that was relieved when they no longer had to work with that stuff. The flourocarbons were a much safer alternative and so much better to handle, although if involved in fire, reaction with copper produces phosgene gas. (The nerve gas used in WWI) In the Refrigeration side of the business, I have never seen R134a cause fires and have never heard of it otherwise. That is not to say there is no problem. Underhood temperatures can be so much higher than a typical mechanical room, not to mention the rubber hoses can seep.I think 134a was a small first step and is not the best way to go, and as far as refrigeration goes, it is being usurped by other, more efficient blends, such as Hotshot, R401a&b,409a,414b and 416a among others. I think (hope?) the auto industry will soon follow. It is a subject that needs more research. Thanks for the heads up.

subcooler

R-134A

Ignition Temps of the 134 are well above 1,000*F. As for the oils in the refrigerant. The lowest ignition temp. is around 800*F and Ester based oils are in the 1,100*F degree range.

Ken_40

Hey Chilly,

Does that guy's rant make sense?

What I know about A/C could be put in a thimble. I'm a wet-head. I just recall doing a few A/C car repairs many years ago and thought his rant was valid - based on what little I know.

Eugene Silberstein 3

A Couple of Issues

I learned early on that when someone says one thing that is suspect, it is very difficult to validate the others. The article mentioned that R-134a is highly toxic, which could not be further from the truth. R-134a has an A-1 safety classification, which indicates low toxicity and no flammability. Other refrigerants that carry the same A-1 rating are R-11, R-12 and R-22.

It is true, however, that pure hydrocarbons are very good refrigerants and that they are highly flammable. Mind you that NO refrigerant poses a danger to the environment or the owners of the equipment resulting from fire or explosion as long as the refrigerant remains inside the system.

Laws and changes to common practices come around as results of incidents that have proven that changes are needed. For example, why are cars now all manufactured with seat belts when those manufactured just a few decades ago were not. Could it be that the powers that be learned that seat belts help prevent serious injury? Why is it now a country-wide law that we all have to wear them, when a few short years ago such wa snot the case?

Times change and, as we get smarter, our technology changes as well. The article that is posted is geared toward one thing and only one thing, and that is selling you a product. More power to him, but just as with the majority of marketing people, you have to look at the information in the context in which it was given.

Glenn Harrison_2

Not a rant, a sales pitch

As I see it, that article is a biased add against R-134a and a sales pitch for HC-12a.

Now the interesting thing is I did a quick search for HC-12a and found ana rticle from the EPA that basically says this stuff is classified as highly flamable, and is not even legal to use as a replacement for R-12.

http://www.epa.gov/ozone/snap/refrigerants/hc-12a.html

Eugene Silberstein 3

My Point Exactly

Thanks Glenn for reiterating the importance of distinguishing between unbiased, objective information and that geared towards generating sales.