[AT] R134a

[Steve W.]

Mark Johnson wrote:
> There is one problem with Red Tek 12A - which you already touched 
> on...flammability. The propane+n-isobutane mix has been known for a good 
> many years - it has all the same useful properties as R-12 - almost 
> identical eutectic curve, carries oil through the system, and so on. My 
> dad (a 1950 engineering graduate) apparently took a 'practical 
> thermodynamics' course where they spent a lot of time studying 
> properties of gases that would be useful as refrigerants. Even as early 
> as the late 1940's, hydrocarbon gases like propane were known to be 
> useful - but the available gasket and seal technology meant that they 
> were too hazardous to use in commercial environments. [As an engineer, 
> Pop was responsible for maintaining the chiller systems for milk and ice 
> cream production at a dairy plant, from about 1952 to 1963.] Propane 
> might have been better than ammonia, even then - but small ammonia leaks 
> are easily detectable, and the stuff doesn't explode!
> 
> I can remember when those 14 oz cans of R-12 were 59 cents at 
> K-Mart...the stuff was cheaper than bottled water. Anybody who could 
> read a gauge set and turn a wrench could recharge their own A/C - which 
> no doubt contributed to the 'escape' problem,  as it was cheaper to 
> recharge the system once a month than to go get it fixed.
> 
> Mark J

That's why it is illegal to use. The guy who was pushing the stuff back 
then managed to blow himself up while demonstrating how "safe" the stuff 
was..


-- 
Steve W.