Hi,

I have searched the archive as well as several other sites.
While people mentioned about that copper core evaporator
cost about half of the original one and last longer. I
can not find the information. in www.worldpac.com online
catalog, I see three evaporators without any description.
And seems they only sell to business customer.

1. How do I know which one is copper core
2. Any other place that sell to individual instead of shops?

Regards,

Tony
1995 850 turbo, 140,000+ miles.

try VPI Volvo Parts independant 713-722-0505. John (the owner nad the guy who anwsers the phone) got me a Copper condensor for my 850and it was about half the price of an aluminum part.

he can atleast call worldpac and ask them for you. I believe that is who he got my condensor from. there truck is always making deliveries there.

Dan

I too have seen where sometimes people suggest that idea here BUT I highly doubt that anyone has ever made one for an 850 or any other car for that matter. If I'm wrong, post proof to the contrary here.
I'm quite sure that there are very good reasons why every evaporator I've ever seen (many) is always aluminum by the factory and I'm sure that it has to do with heat absorbtion as copper probably doesn't work as well.
I know that many radiators and heater cores are copper but I have yet to actually see a copper evaporator for any car.

Now.....IF you want a new replacement OEM evaportator to last longer than normal, Volvo does now make an evaporator "kit" which includes a new accumulator, pollen filter kit and blower motor (brush) air restrictor that's all designed to help make it last BUT it's more expensive to buy/install than an evap only and few people want to spend more money on their AC when given that option as most are probably thinking that they'll have another car by then. It'd be a great idea IF you're the type who keeps a car a very long time.

Copper is a very good conductor of heat and is usually the material of choice where high heat transfer is required - so you'd expect to find it used in an evap. It is easy to solder and repair, compared with aluminium. It is stronger. It is heavier. It is also more expensive ...

As for why anyone would make a core out of aluminium, I suspect you will find the answer is merely the fact it is cheaper to make. Maybe the reason is that it's easier to make the core stand up to high pressures than copper, but I doubt it. Anyone know the reason?

I am curious to hear more about an "air restrictor" for the blower motor. I assume the reason that air is allowed into the motor is to cool it, how can restricting the hole, reduscing the airflow INCREASE the life of the motor.

Puzzled....

KP

OK, the "theory" is that one possible reason why evaps are failing on 850s is because copper material from the blower motor brush area is getting on the evap. "They" then think that this causes some electrical/chemical type reaction when combined with dirt and moisture from incoming air when this "stew" is on the evap and THAT's what causing evap failures. Now.............I have never seen physical evidence of what looks like small holes burned through the exterior or any 850 evap (and I've replaced/inspected MANY), I usually see the dye leaking through the seams at the bottom of the evaps and to me, it "looks like" it's leaking from the inside out. I find the copper brush idea hard to believe (but creative ;)) and think that the real problem is more to do with moisture in the system reacting with PAG oil (which becomes acidic) and burning through from the inside. I've "heard" that that idea has been found to be true on other car makes too. It's then very important to replace the accumulator and PROPERLY evacuate the system using an AC vacuum pump whenever servicing/replacing any part of system, especially if it's been open for a while (like hole in condensor, line and no freon).
Adding a blower motor air restrictor won't cause the blower motor to overheat as they feel there's too much airflow to it as is.
Since evaporators have been failing (a fairly recent occurance in Volvos BUT ever since introducing 134a), there's been MANY "theories" on why this has been happening but most of these ideas I simply don't believe. At first they even said "acid rain's causing it" BUT older Volvo R12 cars drive in the same acid rain (and longer too) w/o evap failures.
I personally wouldn't bother with the idea of adding the tape for the blower motor housing UNLESS I was already there for a reason, like had a reason to remove the blower motor.

Thanks Tim - I get the idea. Pretty creative but I don't believe it either :-) In any case I cannot see how restricting the hole with tape will stop carbon/copper dust particles from escaping into the evap anyway - the motor case would have to be hermitically sealed to stop that. So seems like a waste of time to me.

The funny thing is, if this was truly the cause, then why do approx 3% of 850's have the problem, and not all? (that's according to a survey on one of these internet boards).


Still puzzled

Keith

Tim,

Do you know where is the blower motor air restrictor goes ?

Thanks,

Ching-Ho Cheng
--
1995 855 NA, Bilstein Shocks, K&N Filter

Remove the blower motor and you'll see a smaller hole in the housing where the motor windings get airflow. The restrictor is a piece of plastic tape that covers about 5/8 of that opening. One could use any type of tape really if that's what you want to do.