A/C: Converting R12 system to R134a

[rcy]

Ah...the conspiracy theory...

 

[brianl703]

How long do patents last? How long has R12 been around?

 

[Tosh]

CFC v HFC.
Both harmful to the ozone layer, but HFC less so.

 

[brianl703]

Since the 1930s..so.. if a utility patent (which covers chemical compositions, among other things) lasts 20 years, then the patent for R12 must have expired sometime in the 1950s, if a patent for it was filed in the 1930s.

http://www.lib.washington.edu/engineering/ptdl/faq-answers.html

How long does a patent last?
Utility patents have a life span of 20 years from the earliest filing date of a non-provisional application. Plant and design patents have a life span of 14 years. With the exception of some pharmaceutical patents, only a special act of Congress can extend a patent beyond its term. Utility patents may expire before their term if their owners do not pay the maintenance fees due 3.5, 7.5, and 11.5 years into the term.

 

[Kestas]

Patents are good for 17 years after issue. Inventors are allowed three years for patent approval. During these three years, inventors are allowed to exclusively produce their product before final approval is granted. So if an inventor is savvy, he can stretch the useful (profitable) life of his patent for 20 years.

The fact that r12 has been around for over 60 years is probably why it was only $1 a can before this nonsense.

But that still doesn't take DuPont off the hook for pushing the ban on r12 and profiting from the introduction of its replacement. Now we're being squeezed on the prices of r134, same as OPEC is squeezing us for the price of oil. All we can do is bend over and take it.

Personally this whole issue disgusts me and I plan on using HC (propane-butane) refrigerants out of spite for these big corporations.

 

[kgb007stb]

I am one of those do-it-selfers as well, when I had a minor bump five years ago on my probe I damaged one of the A/C lines which caused all the freon to escape. At that time R12 was not allowed so after replacing the A/C line I bought some freeze 12 and refilled my system to full capacity as stated in the instruction manual. Five years down the road A/C still works, one of the coldest of anyone I know and I remember all my uncles who were mechanics told me that since I did not replace the condenser and evaporator that my A/C would not last a year. Well here I am, zero leakage, and now when it is 112F in LA in about 10 minutes after sitting in the sun all day long I have to turn the knob down because it even get cold for me in the car. This was of course the cheapest solution for me as I was not going to invest into a 10 year old car, but with 15 years total and an original A/C I will be the last to complain!

 

[Kestas]

Since the 30s.

 

[cham55]

quote:

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Originally posted by unDummy:
Try a can of Freeze 12 or R414b

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My AC is out of R12 or almost so. Can I just put Freeze 12 in it and be done? Their website makes it seem that way. (unless equipped with a High Pressure Relief Valve, a High Pressure Cutout Switch must be installed - whatever that means)

 

[cham55]

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