Air Conditioning

[n2vsw]

In searching for a complete air conditioning system for my 914, I've had people Email about converting to 134A. I thought I'd post my response here in case it helps anyone out.

Ok my first recommendation if your going to rebuild the York is to replace it with something else. There are rotary compressors that are made to specifically replace the Yorks. They bolt right in to the existing mounts. They are available in R12 or R134A. The reason I say this is that the York is a reciprocating compressor that requires 12 horsepower to operate. A typical rotary only about 1.5 hp. That's allot of horsepower on a car that doesn't have much to spare. Other than that there's no other reason you cant use the York. Ok here the scoop on the 134A to R12 conversion. First off if you use 134 then you have to get all the mineral oil out of the system. You have to flush everything out to remove any mineral oil residue using a commercially available flush or plenty of acetone. Then refill with PAG or compatible 134A oil. Then you have to remove all the rubber o rings and replace them with the green Nypril ones. The new oil eats the old style rubber orings. Good luck trying to get the green orings and seals for the York. Then you have to replace the hoses you have that are just plain rubber with the vapor barrier type hoses. Not only will the 134A gradually begin to eat away the rubber but it will also bleed through the hose. The 134A molecule is smaller than a R12 molecule so it literally leaks through the hose. The more hoses you have the more it leaks due to the length. In a 914 you have some pretty long hoses going from the engine compartment to the front of the car. The new style of hose won't leak at all. A useful hint to you, find a shop that makes hydraulic hoses and ask them to make you up a set of A/C hoses. They carry vapor barrier hoses and every conceivable fitting you might have on the ends as well. I had a set made up for a Pantera that were 8 ft long each and they charged me $30 for the pair. Just have to call around. After you do all that then you can add 134A. Here's the problem. R12 can absorb latent heat about 20% better than 134A. This means that if you keep the same size condenser and evaporator and convert to 134 then it will be 20% less effective. New cars using 134A have evaps and condensers 20% larger than what would have been required 15 years ago using R12. You obviously can't get a larger evap and condenser unless it was custom made for mucho $$$ so if you convert be prepared to deal with less cooling. There is hope though, you can use something called Freeze 12 which is a drop in replacement to R12. You don't have to change oil and is actually about 15% COLDER than R12. You just have to add about 15% less to the system to compensate. You do need to change the hoses though but not the seals in the compressor. The catch is you need a license to buy it. You can get info at this link:
http://www.freeze12.com./

It tells you how to get the license, it's $20 and you take an online test. If you pass it then you can buy it at most auto supply places and it costs the same as 134A about $6 a can.

The other option is to use R409, it's an exact replacement for R12. The automotive sector doesn't know about it because they don't have the license to buy it. The air conditioning and refrigeration industry has used it for years as a replacement in freezers, walk in boxes, deli cases, etc. It's sold in a 30lb can for $180 That's $6 a LB as opposed to 134A that is $7 for 12 ozs. You have to get an A/C guy to get it for you though because of the license requirement. I've bought I don't know how many cans for people who then split the cost among friends who need R12.

I've found that most of the people who've removed the A/C from the 914's because it doesn't work right is due primarily to the leaking hoses. That and the lack of R12 and an easily purchased replacement. If your considering using 134A don't waste your time because it won't work right and you won't be happy. Get Freeze 12 or R409 Hope this helps

[Special K]

There's also a drop-in replacement refrig. called "Hot Shot" R-414b. It's 8% more efficient than R-12, and costs about 1/4th as much as R-12. I've used it on a beer cooler at a local pub (worthly cause), my own refrigerator, and several friends cars with great success. The pressures ran much lower to produce the same superheat temperatures, requiring less amp draw (i.e. "horsepower"). As with all freons, a license is required to purchase. Just get a friend that's in the HVAC biz to get you some.


P.S. !!NEVER!! get caught venting any refrigerant. There's a $50,000.00 dollar fine, plus $10,000.00 per lb., per unit capacity.

[Special K]

Oops, here's the website for the R414b, if interested.

http://www.icorinternational.com/hotshot/hotshot_opening.html

[captjm]

Just wanted to say thanks for the info!

[Va914]

Thanks also.
Now if I can find someone to sell me a A/C system I would be all set come next summer.

Kerry