Lets talk automotive refrigerant.

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  • netcsk
    E30 Mastermind
    • Apr 2004
    • 1609

    #1

    Lets talk automotive refrigerant.

    So, we went over the common refrigeration cycle in Thermo. today and after class I talked with my professor (who actually works in this field, he's just filling in this semester) about refrigerants.

    First of all, if you don't know, The number of the refrigerant tells about the molecular structure. If you take the number (R-134) and add 90 to it, you'll end up with 224. This means there is 2 Carbon atoms, 2 Hydrogen atoms, and 4 Fluoride atoms. The "a" on R-134a means the layout is asymmetric.
    If you know some chemistry, you can draw it out yourself.

    If for instance you have R-12: 12+90 = 102, which gives 1 Carbon atom and 2 Fluoride atoms. You'll notice that there should be 4 atoms bonded to the Carbon; the remaining 2 are Chlorine (and Chlorine is what eats the ozone).

    Anyway, on to my point.
    I've heard rumors floating around talking about the stopping of R-134a and the connection with the ending of a patent. I asked him about this and he said that the reason there is talk of ending it (and why Europe has already switched away) is due to the fact that it is a contributor to green house gasses and nothing to do with patents (it's been up for many years apparently).

    Europe is using a hydro-carbon refrigerant in their automotive field as of right now. I believe he said propane (maybe kerosene -- don't remember). We of course cant use this due to the flammability factor (same reason R-152a isn't used) and our sue happy nation when something would inevitably happen.

    So, in his opinion, R-134a is here to stick for quite some time in this country.

    *The above is not my knowledge -- I make no attempt to pass it off as my own* hehe.
  • 92 mtechnic cabrio
    Honesty is not the best policy!
    • Dec 2003
    • 4907

    #2
    so um, is R-134a better than R-12?

    I wanted to know how much efficiency they had to cut away when switching to a different refrigerant.
    R.I.P 07/01/09 - 04/23/10 :(

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    • netcsk
      E30 Mastermind
      • Apr 2004
      • 1609

      #3
      Hmm, I can't tell you exactly as far as efficiency. Unfortunately, my book is new enough to not include the values for R-12. I'll see if I can get something out of him.

      Oh, an no it's not a better refrigerant, it's just safer for the environment.

      Comment

      • Mike325
        No R3VLimiter
        • Mar 2006
        • 3685

        #4
        He was talking about the use of propane. It is very cold in a liquid state.
        Originally posted by cabriodster87
        "Honey? What color is this wire? Is it the same as that one? Are you sure? I don't believe it. OK, it works. Thank you sweetie."
        Originally posted by Kershaw
        i've got a boner and a desire to speed.

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        • backtrail69
          R3V Elite
          • Jul 2005
          • 4471

          #5
          R-12 in my understanding is a better refrigerant, but R-134a is much better for the environment, that is why we switched in the 90s to R-134a pretty much exclusively.. My eta and Lincoln Roll with R-12 and the A/C rocks...but a properly designed R-134a system works just as good. Converting the R-12 systems usually ends with shitty cooling because the system was not designed for it.
          :: PNW Crew ::
          '87 325 4dr, '74 2002

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          • Jscotty
            Banned
            • Jan 2007
            • 2285

            #6
            I knew a guy who was an HVAC tech who claimed to put R-22 (which is used for household systems) in his work van and this was the reason why the AC was shooting out snowflake sized ice chips intermitently. I don't know if this was true or if he was just BSing me but the inside of his van was as cold as a walk-in refrigerator.

            Comment

            • stevofthahill
              R3VLimited
              • Apr 2005
              • 2468

              #7
              I love my r-12, it works so much better than 134a in the az summer.

              Comment

              • AdamF 88iS
                R3VLimited
                • Oct 2003
                • 2051

                #8
                Originally posted by backtrail69
                R-12 in my understanding is a better refrigerant, but R-134a is much better for the environment, that is why we switched in the 90s to R-134a pretty much exclusively.. My eta and Lincoln Roll with R-12 and the A/C rocks...but a properly designed R-134a system works just as good. Converting the R-12 systems usually ends with shitty cooling because the system was not designed for it.
                True. R-12 has loads of CFCs which contribute to the whole O-zone/global warming thing. R134a requires a lot higher pressure to work as well as R12, which is why most converted systems have a tough time working as well.
                Adam Fogg- '88 M3

                Common sense- It's the new 'gifted'

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                • RobertK
                  Kicked cancer's ASS.
                  • Jun 2005
                  • 5864

                  #9
                  What's funny is that R152a is not as flammable as you think when it comes to practical use as an automotive refrigerant. Many commonly used HC r134a blends contain propane or isobutane which makes them more flammable than canned air.

                  After doing some research on the subject here:



                  I converted my 92 325is over to r152a using canned air instead of using r134a. Been working great for over the past month.

                  Comment

                  • JPL
                    Mod Crazy
                    • May 2005
                    • 774

                    #10
                    yea anytime you put a different refrigerant into a system designed for a specific kind you aren't going to get the same productivity. i've also heard that r-134a leaks more easily. also i was talking to an a/c mechanic and he was saying that r12 price is going down and is down because they overestimated the demand for it when they stopped production. the factories were at full production when they were told to stop so there's a shitload of it left. i'm getting my a/c recharged for 90 bucks which includes evacuation, leak check, and the new r12. thats way less than what i was expecting. that doesn't include if he finds leaks but hopefully he won't even though my system has been dry for a few months.
                    Originally posted by Hawt drift chick
                    Yeah, i'm a good dude i swear, i just like to be balls to the wall.

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                    • Tree18is
                      R3VLimited
                      • Mar 2004
                      • 2703

                      #11
                      ROBERTK! your sig wins, everything! nice.

                      no comment on ac btw.

                      Comment

                      • Jscotty
                        Banned
                        • Jan 2007
                        • 2285

                        #12
                        Originally posted by JPL
                        also i was talking to an a/c mechanic and he was saying that r12 price is going down and is down because they overestimated the demand for it when they stopped production. the factories were at full production when they were told to stop so there's a shitload of it left.
                        Also, I think this has to do with the fact that the average schmuck on the street was not allowed to buy R-12 after the ban went into effect. They only let licensed mechanics and anyone with a freon license purchase it. The 134a retrofit kits are relatively easy to use also. I bought one in lieu of going to the shop to have R-12 installed in the system. So after I let out all of the R-12 I followed the instructions by first installing the new fittings and releasing the oil conditioner into the system. After that I put the freon into the system and it worked great

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