[DML] Re: Air Conditioning / Clicking Noise

[Mark Noeltner <mnoeltne@xxxx>]

I agree that new cars use R-134 and have cold A/C, but that is because they
run larger compressors than earlier models. R-134 does not have as good of
a cooling coefficient as R-12. Also, R-134 runs hotter than R12, so you can
only run R-134 at approx. 80% of the pressure that you could with R12 to
keep the heat at the compressor the same. That's why the newer ones have
larger compressors. Combine these two things and you can see that R-134 in
a system designed for R-12 isn't going to cool nearly as well.

Now don't get me wrong. R-134 is fine and dandy for newer cars that are
designed for it. It MAY be safer for the ozone layer (despite lots of media
stories, the jury is still out as far as actual scientific facts). So I'm
not advocating using R-12 in new cars. Just in cars that were designed for it.

Mark N
VIN 6820


At 02:56 PM 5/27/99 -0700, you wrote:
>Actually most R134a Conversions only require the oil to be changed. I
>am pretty sure that it runs at similar pressures as the R-12. A basic
>conversion kit consists of the new oil, different fittings (for filling
>and draining the system), and a few pounds of R134a. Also, the
>performance difference between R134a and R-12 is very small. Remember
>that all new cars use 134a, and their A/C can be very cold. Really, the
>difference is only a couple degrees F, and r-134 is MUCH safer for the
>ozone layer. Don't knock R-134a until you try it (or in someone else's
>car).
>

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