Year: 1988
Make: BMW
Model: 635csi
Engine Size: 3.5
Refrigerant Type: r12
Country of Origin: Germany
Looking for a definitive answer to this question in general. Can a new parallel flow condenser be used with r12, in an r12 system and are there any benefits or concerns involved?
For context, my '88 BMW has marginal air and general consensus is that they were marginal for south Ga heat from new. So looking into this as an upgrade.
There's no reason why it woudn't work. It may not help much though, because the limit with European cars was typically driven by their use of small evaporators and evaporator blowers. If it is reaching the point where the compressor cycles off, the evaporator is already as cold as it can get, and improving condensation performance under the hood won't make the inside of the car any cooler.
I fully agree with mk378. Some vehicles had inadequate systems from the get go due to small evaporators. You migh investigate the possibility of adding a second evaporator; possibly located in rear deck shelf. If your present evap has a rating of ie: 4000 BTU and your heat gain is 6000 BTU, it won't handle the load. That is the reason why some vehicles are not recommended for R134a conversions.
No reason you can't use a PF condenser with R12. As for performance gain it will depend on the pressure you have with your current condenser as far as how much will be gained.
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Very typical of the older German cars. Absorb cabin heat (evap), reject heat (condenser). If you cannot remove more from the cabin; being able to reject more with a more efficient condenser, is moot.
Growing up in S. GA. I found that adding a 12v fan that plugs in the cigarette lighter helps. Once you are good and soaked, the swamp cooler evaporative cooling principle does work.
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Hey guys,
Thanks much for the quick replies! The car does have dual air, and a second evaporator in the rear (obviously a factory afterthought to fix a small front evap). Some e24 owners have put bigger condensers on and had good results, one guy put dual parallel flow conds on his car and 134 and had great results! Of course this is only testimonial feedback, and I take it as that. I'm definitely not knowledgeable in ac, but I would like to learn more. I'm probably going to change the condenser, and if a parallel flow with r12 wouldn't hurt, I'll probably do that instead of the stock tube and fin.
Bill
Before you invest $$$, may be mist the condenser with a hose for a while and see if the vehicle gets colder?
And if misting helps, then the condenser and or fan could benefit from improvement correct?
Concerning flushing, this car has two expansion valves, and the front valve is INSIDE the evaporator housing in the dash ! Already been there with my first bmw e24 and had to remove every line and every component in the car, front to back, to flush it.
With the system as is, both units blow cool air, and functions properly including cycling the compressor, but is low on charge as I didn't want to waste more r12 until I had a better game plan.
Can I just flush the condenser only and recharge to get a baseline, or could that cause more problems? Reason is, it had a leak when I bought it that turned out to be a very loose condenser line nut. I know the PO probably ran it like that for who knows how long, and the car sat idle for probably a year. So I'm thinking it may be less than clean. I do have a good AC mechanic I can have evacuate the system, but would that remove contaminants? It's a complicated system as far as access to components and since the compressor is running properly I want to get it going as best I can without digging too deep or killing a compressor.
I'm thinking if I flush the old condenser and charge/check for leaks, and it cools to say low 50's at the center vent at best (kinda what I expect), and misting the condenser helps then I would be game to fit a universal PF condenser. Am I on the right track?
And forgive me if these questions are rudimentary (I'm at AC level 101), or if I ramble a little(adhd!).
But your help is very much appreciated.
I just read this:
FLUSHING TECHNICAL PAPER vs2.pdf
and I think I just stepped into an abyss...
If you are just changing the condenser on an operating system, and keeping it R-12; you can get away with adding a couple of ounces of mineral oil just for the condenser replacement. Its a WAG, even more so when you have doubts if the current oil quantity is correct, or if you suspect it is tired or contaminated.
Flushing all the components intended for reuse to a clean and dry point is the only way to get to a baseline necessary to KNOW how much and how good the oil in your system is. TXV's buried (in this case 2), do not present an easy flushing solution. But if you want to refresh the entire system, it is what you will need to do.
I am glad you read the "Flushing Tech Paper"; seeing the "abyss", before you blindly step in it, is exactly why I put it up.
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I did not know that. Thanks.
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I bought a can of 134a at w**-mart that had a stop leak, oil, and dye in it. It also had a hose and a gauge, so now I'm an AC pro!
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