Fox T-Bird/Cougar Forums  

Then why do conversions WORK???? I have dun HUNDREDS with absolutely NO ISSUES!!! So question to posters. How many of you converted to RA134A and does your system work.

Is R134a less efficient than R12 ?
R134a is NOT less efficient than R12. Actually R134a is more efficient so it needs a bigger condenser. BUT the condenser in a modern car are quite adequate for conversion. As i posted a bigger condenser is always better but not necessary. Remember when converting you always down charge with 134A  by 10-15%. This is because 134A is more efficient. So change out your condenser that is always a good idea but it is not NECESSARY. Just saying. Thanks

Ok Jeremy B i have a supply of R12 not only in one pound cans i also have several 30 and  50 LB JUGS. How much do you want. If a 5% reduction in cooling will make you AC system UNBEARABLE i will send you the proper amount of R12 and the proper oil to change back to R12.  CASE CLOSED!!!

Based on theoretical calculations, performance tests and information gained from other tests, such as those reported in this paper, HFC-134a is not a "drop-in" replacement for CFC-12 in most automotive systems.

Thus, this testing revealed that at idling condition HFC-134a is inferior to CFC-12 in both compressor power consumption and cooling capacity. An increase in condenser capacity is required to offset such deterioration and equalize the performance of the air conditioning system.

Numerous tests conducted at Sanden have shown that the performance of an A/C system retrofitted to HFC-134a may be either inferior or superior to the original CFC-12 system. The greatest influence on the performance of a retrofitted HFC-134a A/C system is the efficiency of the condenser. The higher the discharge pressures, the more the performance and durability will suffer. If discharge pressures are in excess of 2.5 MPa at 25 OC ambient temperature then the remaining compressor life may be seriously reduced. The need for improved condensing performance when retrofitting with HFC-134a should be determined on a vehicle to vehicle basis.

However, retrofit development must also consist of identifying conversion kits for each vehicle that will maintain equivalent performance (within +/- 1.1°C discharge air temperature and +/- 103.4 kPa compressor discharge pressures) to the original CFC-12 system.
It is imperative for the retrofit system to compensate for the lost condensing capacity due to the higher vapor pressures that are characteristic of HFC-134a. To address this issue, seven wind tunnel facilities were used to identify the worst case body style, power train and engine combination of each vehicle line. Once identified, these vehicles were used as the basis for developing performance packages to be included in the retrofit conversion kit. Condensing capacity and compressor discharge pressure were improved by one or any combination of the following: adding air deflectors or seals, modifying existing fan control strategies or designs, adding pusher fans, or upgrading to a high performance condenser.

It has been verified that the refrigerant charge amount is reduced proportional to the difference in liquid density, resulting in a 7% overall reduction charge amount.

Road and vehicular wind tunnel tests confirm PFtm condensers equal the performance of conventional serpentine condensers, while requiring about 25% less refrigerant. In addition, PFtm condensers weigh less and offer installed volume savings. These characteristics will become assets, as supplies of refrigerants are reduced and under hood space becomes more limited.

SO we both have the same credentials. Funny thing is R12 is getting cheaper by the DAY. And 134 is sky rocketing. Could the 1234yf be in our automotive FUTURE. They approved it and it looks like a GO!!!  Hay i did not know you were licensed and the offer i made you was a genuine one. Some might think i am a PRICK but i always like to help people HONESTLY i would have sent you everything including a CAN TAP. Thanks.

Now what will i do with the R12 and 134 Manifolds and reclaiming machines that will be collecting dust i have ??? Guess they will go in the pile of obsolete specialty tools like a VEGA timing belt tensioner tool. And as usual the pressures keep on getting HIGHER . Gm is using 1234yf in model year 2013. Time for new stuff again. But the plus side is i think it might be a gas that can be vented. The EPA has not answered this question. Going to be interisting. It is claimed it can be a substitute for both 12 & 134. Thoughts???  Thanks

Here's a question, anyone ever convert to R-134 then back to R12?  When I converted mine I put in the new acspoogeulator, orifice, and condenser, and it just plain sucks here.  Texas 105* summer heat and 50-70% humidity on a daily basis in July....  Call me a wimp if you want, I like it COLD!  I'm thinking of going through it all again, replacing the acspoogeulator and condenser, and flushing the  out of it again.  Just didn't know if anyone had tried that and it worked.  I'd rather get the R134 working right, and I hadn't tried the bigger condenser yet.  I have a huge electric fan too, so I know that's not a problem.