A/C efficiency - a bridge too far

Discussion in 'The BS Topic' started by ULTM8Z, Aug 26, 2020.

  1. ULTM8Z

    ULTM8Z Veteran Member

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    So I think I finally jumped the shark going after more A/C efficiency... lol...

    I thought I'd seal the condenser against the radiator support to ensure the fan only pulls air through the condenser and not around it, thinking I'd improve the heat transfer off the condenser.

    Ironically I didn't really notice any improvement in efficiency (actually not surprised given I already have ~37-38F air out the vents), but what I did get is a huge increase in engine coolant temperature. It was about low 90's today and I took the car into work. On the way back, the coolant got well over 200F while in traffic. Typically on a day like this, it'd stay between 180 and 190F.

    Without that seal, what was probably happening was the fan pulling through the radiator a mixture of air pre-heated by the condenser as well as ambient temperature air going around the condenser.

    With the seal, the radiator was exclusively getting preheated air off the condenser. Coolant temp actually bounced off 210F.

    I'm going to add that seal between hood and radiator support per my other thread (since its a factory item), but at this point I think it's time to leave the A/C setup alone. :p
     
    Last edited: Aug 26, 2020
  2. muscl car

    muscl car Veteran Member Lifetime Gold Member

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    This is awesome you can get an AC system to work efficiently in a early 2nd gen . I rely on a spray bottle that has water in it and spray my face when it gets hot when driving my Camaro
     
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  3. Gary S

    Gary S Administrator Lifetime Gold Member

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    I take the easy approach to A/C in my Camaro. It doesn't have A/C so my solution is to leave it in the garage on nasty days and drive it only on nice cool days.
     
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  4. Twisted_Metal

    Twisted_Metal Administrator Staff Member Lifetime Gold Member

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    You’re doing great with those vent temps!

    You’re probably right about the airflow with the added seal around the condenser.

    What compressor did you use?
    Can it be used with R12?
     
  5. ULTM8Z

    ULTM8Z Veteran Member

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    Although I don't enjoy driving on really hot days with the windows up, I still want it to perform well if I do.
     
  6. ULTM8Z

    ULTM8Z Veteran Member

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    I'm running a Sanden SD7 (7 piston). The CAA typically comes with a 508 (5 piston). I was running an R4 due to the serpentine brackets, but it was power hog and didn't really put out good performance with the CAA system. But when the R4 failed, I found you could adapt a Sanden onto serpentine brackets. The SD7 had the serpentine pulley and the ports in the right locations so I went with that.

    The 37-38F vent temps were originally measured when I charged the system in ~85F weather. My guess is on 90F+ days, it's probably around low 40's. But it's still coooold, verrrry cold... lol.

    And with the ceramic window tint blocking so much infrared getting into the car, I rarely have to run the system even at medium blower speed.

    I did do a few other things beside the window tint to help efficiency though... I covered the vent hose behind the dash with foam insulation. Even with firewall insulation, it probably still gets warm behind the dash due to engine heat, and that hose is long with very thin plastic walls. So the air stream probably picks up heat on it's way to the vents. And also due to underdash heat, I put a heat shield over the blower motor intake such that it only takes in and recirculates air from where people sit (as opposed to picking up air from behind the dash and fighting engine heat).

    I'm sure the Sanden run on R12 (Sandens were around when R12 was)... you just have to charge to R12 pressures.
     
    Last edited: Aug 26, 2020
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  7. woody80z28

    woody80z28 Veteran Member Lifetime Gold Member

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    My hope all along for the Camaro is that my Lizard Skin insulation and perfectly sealed holes for trans hump and clutch master now will keep sweat from pouring off my face like it used to...

    But I bought all the A/C tools and got the dead A/C in my Beretta and truck working pretty well. So I may end up doing a conversion for the Camaro too. A big ol compressor is gonna wreck my race car vibe under the hood. But A/C is niiiiiiiiice.
     
  8. Twisted_Metal

    Twisted_Metal Administrator Staff Member Lifetime Gold Member

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    I'm still trying to figure out which compressor to run.

    I intend to replace the entire system under the hood.
    It worked well but I knew I had a couple of leaks (compressor seal and a hose) and then the evaporator sprung a leak and dumped oil inside the evaporator case. :(

    I've got all of the other factory replacement components purchased... Condenser, accumulator, hoses and evaporator, with the orifice tube installed, along with the evaporator service kit (seals for the box.)

    I also have the vacuum pump, a supply of R12 and hoses/gauge set. (I rebuilt the A/C in my Jimmy.)
    My windows are tinted too.

    I know you need to run mineral oil for R12. So... the compressor has to be emptied if it comes with PAG
    I haven't seen a Sanden compressor with a single V pulley. (I intend to keep the V-belt system.)

    I'll have to look into the Sanden SD7 as that is one I haven't checked out yet.

    Thanks for the info!
     
  9. CorkyE

    CorkyE Veteran Member Lifetime Gold Member

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    I put a Sanden SD7 on my serpentine setup a couple years ago, replacing the (short lived) R4 also. Mine came with oil, had a sticker on the box, so that's something you'll have to address if you stay with R12. I bought mine on EBay, but I called the dealer first. There are a lot of Sanden look alikes so be careful, make sure you get the real thing.
     
  10. ULTM8Z

    ULTM8Z Veteran Member

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    Exactly. Get an OEM sanden, not knock off "Sanden style".
     

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