R-134a conversion in an Auto A/C System 2

[Bill93XJ]

I have heard that when an automobile system is converted from R-12 to R-134a that the charge should be 'lighter'. Say approximately 80% of the capacity of the O.E.M. R-12. Does this mean the cooling capacity of the system is now diminshed by 20% ?? I know that systems which are designed from scratch to use the R-134a refrigerant will have copper instead of aluminum in the condenser/evaporator coils and this is because of the improved thermal conductivity. So when the R-12 is swapped out for R-134a you are already handicapped by the aluminum components. What about the less dense charge? Does the converted system have a chance of reaching the same cooling capability as the original? If not, what compromise is considered 'reasonable' ?? Thanks in advance for any help from all........ Bill93XJ

 

[GT6Steve]

Excellent thread that brings another question.
I'm restoring a 60's car with an add in system. It has about fifteen feet of hose running under the car to the trunk mounted evaporator. I want to replace these with tubing. What materials are acceptable for this. Obviously aluminum as this is offered for sale. How about Copper? Steel hydraulic line?
Thanx in advance, Steve

 

[evelrod]

Folks are staying away from this one, I guess, Steve.
Back in the late 50's when I was working in a garage to pay my way through school, I did several AC installations (paint by the numbers) and helped in the repair of a couple Buicks and Cads that had the evaporator in the trunk. You might look up the particulars of these installations. Buick or Cad club, perhaps. The cars were around 55 models as I recall.

Rod

 

[pennpoint]

GT6Steve
You have a unique installation. Do not compromise it by going CHEAP here. NO copper/NO steel/Stainless is better.
You can buy Stainless Steel flex tubing for a good price. Use riged aluminum (insulated) where necessary, switch to flex at those points. Seek manufactures as "Pacific Flex" or derivations of:
Come back here if no sites can be found.
Dollars are a few different, quality is enjoyment.
Be proud, buy the best type conduit system because you have done nothing more than that since you purchased that damn thing (car) inthe first place...
It's a thing of beauty to see somone rebuild a system like this using SST material. Yes it's a little more money but when you see someones eyes light up because they KNOW the extent of the effort. Stay the Course.

Wishing you Well

pennpoint