applies to ac evaporator. 96 Dakota. I see both styles available. serpentine type is double the price. at least on rockauto Worth it? What is difference? which is better and why? looked on Ebay and found a deal on a serpentine as cheap as some of the plate and fin and actually marked made in USA whereas any plate and fin style that I can see anything about country of origin on with the plate and fin style, seem to be China. I try to avoid made in China whenever possible. I know that isn't the only difference between these 2 types of evaporators.. I have also heard of serpentine as related to condensers

the only thing I have ever heard about serpentine condensers is that you know how they suggest a system flush when replacing a compressor? those same people claim that a serpentine style condenser is pretty much a mandatory replacement instead of flush out when a compressor dies. but I don't think I'd know a serpentine condenser if I seen it.

(unrelated side note I miss the separate belt accessory drives, not really crazy about serpentine in that department)

 

This is just my opinion, but I would prefer a serpentine.... assuming there is not a big difference in efficiency.
FWIW I believe you are backwards on flushing. A serpentine, one continuous loop, can be flushed..... A plate style cannot, due to the flush will just take the easiest path, and not push out the debris in the evap.

IMO plate style are cheaper to manufacture, but for us, I fail to see the advantage.

If you "Google" the subject there are several articles on the subject. example. https://docs.lib.purdue.edu/cgi/view...&context=iracc

 

you mention efficiency. that's probably the difference, which design is better.... am I to assume that more expensive (serpentine) is more efficient?
not that I would think it would make that much difference considering the size of a Dakota cab
but yeah... if I were trying to cool something like a full size van then yeah I would want the most efficient thing I could find.

 

Serpentine isn't as efficient and is more prone to plugging up in the real world.

Plate and fin has the advantage there's SEVERAL paths for the fluid/gas (be it coolant in a radiator, transmission or engine oil up front, or refrigerant) to flow.

Also, on coolers like for a transmission, it tends to self-regulate, and not be as involved when said transmission or engine oil is cooler.

For A/Cs, a plate and fin evaporator exposes more metal in the same area, with no increase in restriction; this allows for more efficient cooling of the vehicle's passenger area.

But you're right, on something the size of the Dakota, using the same compressor used on bigger vehicles, it's not that big a deal.

RwP

 

wound up scouting Ebay last night and found a serpentine for the same as/less $$ than many plate and fin... the pix of the plate and fin looked like they were stamped from a cookie cutter, looked very cheaply made... and any that I could see anything of a Country of origin showed China... found a Delco serpentine, even had a production date sticker on it, from way back in 2001, made in USA which helped me decide right then and there... I DON"T want to do the same job on the same truck twice so I don't want a cheaply made POS....
As it is both my trucks I gotta pull the heater box before winter... so I already gotta do the job twice. Right now my main worry is not wanting any redo's... I don't want 2 heater core jobs to morph into 4 because of shoddy product.
I know these trucks are old already and wont be around in another 22 years... but they don't make parts today like they did then either.

but I was also asking "in general" as I have a project car that don't have AC that I may add it to, and wondering which is best and why for when I get back to working on that thing.... if I even have the choice when I get to that point (hint... car is 1st part of my username)

 

Quote:

Originally Posted by RalphP

Serpentine isn't as efficient and is more prone to plugging up in the real world.

Plate and fin has the advantage there's SEVERAL paths for the fluid/gas (be it coolant in a radiator, transmission or engine oil up front, or refrigerant) to flow.

Also, on coolers like for a transmission, it tends to self-regulate, and not be as involved when said transmission or engine oil is cooler.

For A/Cs, a plate and fin evaporator exposes more metal in the same area, with no increase in restriction; this allows for more efficient cooling of the vehicle's passenger area.

But you're right, on something the size of the Dakota, using the same compressor used on bigger vehicles, it's not that big a deal.

RwP

Ralph, I dont believe this is correct.....

The evap. is very different then a heater core, or radiator.
In an evap. the refrigerant is injected as a liquid. It boils off and absorbs heat, taking it back to the compressor, .....
Its the changing of liquid into a gas that does the cooling.
That being said, I believe it is much easier to control this process with a serpentine coil.

As far as a blockage, on a AC system this would not be a problem, unless something comes apart. ie. drier, compressor, etc. Otherwise they are perfectly clean inside, so multi passages would not be of any help.
In fact, I believe because of this multi flow, in the event of a system failure, replacement of the evap. would be required,

I work in the HVAC industry, mainly dealing with residential equipment.
In short, I have never seen a plate and fin design used..... And believe me, for the past 10 years, they have been making changes to make equipment as efficient as possible.

 

I agree with 93.i used to design environmentally controlled rooms and chambers that are essentially very expensive and very specialized refrigeration systems. We only used serpentine evaporators.

Ideally you want your refrigerant boiled off by about the 3/4 mark. The last quarter of the evaporator is essentially just superheating the gas. I think that a serpentine evap will give the liquid much more time to gradually change phase and change temperature instead of having to do a sudden temperature change quickly. It'll also help ensure all your liquid is converted to gas with an even superheat.

Edit: Disregard above post, after some research I had my terminology mixed up. I'm unsure which will be preferred.

 

I bow to your practical knowledge; I was repeating what an engineer had told me a few years ago.

RwP

 

Duh wrong thread

 

well the serpentine is in my 96 now, original was plate and fin. Even though it is more money most places, the serpentine is smaller physically. I put plenty of foam weatherstripping in the space where the evap fits in the heater box, but even with all the sponge, it is still loose in there. when I went to snap the fittings onto the evap on the engine side, I had to lightly hold the evap tubes with a pair of channellocks to get it to snap instead of just slide back n forth.... that says nothing about how it will function.... the weatherstrip that I used was very squishy foam, gotten from the hardware store. I used 1-1/4X1-1/4" square "air conditioning to window opening" stuff for mounting a window AC into your house. hopefully as an AC works, it don't soak up the water (condensation) and get moldy in there on me.... the plate and fin is definitely a better/tighter fit in the heater box.....

and as it turns out, Its a good thing I was putting a heater core in there "while I had it apart anyways" because yeah it was leaking. I put a HC into my 92 2 weeks ago but didn't replace the evap because I don't care about AC in the 92.... Though I wasn't getting any steam on the windshield in the 96 like the 92 was starting to do, it was definitely leaking worse than the 92 was, and in a different spot. the 96 was leaking in the diagonally opposite corner from the hose connections where the core met the header, where the 92 was seeping from midway up the core about 1/3 of the way from the "back" (further from the inlet tubes) header. on the 96, the bottom of the heater box was wet with antifreeze where it wasn't on the 92.... yet I didn't have any fogging of the windshield on the 96 and did on the 92.
I only smelled antifreeze occasionally on the 96 and almost constantly on the 92 until I changed it. Neither leaked enough to show low at the radiator cap or within the reserve bottle.

I just wish that I could have found replacement heater cores that were made somewhere OTHER than China.... THAT pisses me off. and that I could have found copper/brass, all I was able to get was aluminum replacement. Even though the autozone Ebay ad showed copper and brass in the ad..... their online site linked to the local store only showed aluminum, I got exactly the same ones via Ebay at the same cost as I would have paid in the store-- same brand and PN too..... If I would have known this, I could have saved me $20 ($10 each truck) by buying the same exact cores as I wound up with, elsewhere online.... so far the one in the 92 so good, but not holding my breath I still gotta finish putting the dash back together, Im doing this outside, it rained last nite, waiting for the driveway to dry a bit so my legs don't get wet as they hang out as I lay partly in the truck and partly on the driveway haha...…

also on the 92 I didn't have to pull the radio/ the 96 I had to, the PO did a very half-assed **** poor job of putting the aftermarket radio in, pulling it was the only way to get the wad of excess wiring out of my way so that my heater box would drop out.... it was enough to pinch and bind everything up.

and the 96 was a bit more of a PITA to finagle the heater box in and out because of the difference in accumulator... the 92 has a flat plate for an H halve (expansion valve) that doesn't stick out of the heater box as far as the tubes do in the 96, which gave me less room under the dash to the firewall to sneak it into and out from under there. from when I looked up my parts the heater core is the same 87 til around 2000 Dakotas, (fits old minivans and K cars too) the evap changed from '94 on up-- around the time they went from R12 to R134...….