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Technical Will painting an AC Condenser affect cooling?

Discussion in 'The Hokey Ass Message Board' started by BJR, Feb 14, 2022.

  1. BJR
    Joined: Mar 11, 2005
    Posts: 7,530

    BJR
    Member

    My 49 Buick has an aluminum ac condenser that you can see through the grill. Can I paint it flat black, so it dissapears without affecting the cooling performance? Buick front w bumper.jpg
     
  2. BamaMav
    Joined: Jun 19, 2011
    Posts: 5,580

    BamaMav
    Member
    from Berry, AL

    Some will say yes, but I've never noticed a difference. I'd just put a thin coat on it, not try to get it thick.
     
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  3. seb fontana
    Joined: Sep 1, 2005
    Posts: 7,463

    seb fontana
    Member
    from ct

    Painted mine and work great.
     
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  4. Pass The Torch
    Joined: May 18, 2018
    Posts: 1,019

    Pass The Torch
    ALLIANCE MEMBER

    Just paint the front half... You'll have air flow, so my guess will be that it should be just fine, vs baking in the sun, soaking up heat.
     
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  5. mgtstumpy
    Joined: Jul 20, 2006
    Posts: 9,125

    mgtstumpy
    Member

    Even if black, being in the airflow would still allow it to dissipate heat A couple of light coats should be sufficient to mask the front view behind the grill and not impede airflow. I'd ensure that only necessary coverage would be sufficient. Be careful not to overdo it and only coat the surfaces so as not to adversely affect the cooling efficiency and performance of the condensor.
     
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  6. Blues4U
    Joined: Oct 1, 2015
    Posts: 6,627

    Blues4U
    Member
    from So Cal

    A coat of black paint should help it shed heat more efficiently, a dark surface emits heat far better than a light or shiny surface.
     
  7. PhilA
    Joined: Sep 6, 2018
    Posts: 1,523

    PhilA
    ALLIANCE MEMBER

    Matte black. A real thin coat just enough to change the color, will be fine (technically better than a glossy silvered surface).

    Phil
     
  8. jimmy six
    Joined: Mar 21, 2006
    Posts: 11,248

    jimmy six
    ALLIANCE MEMBER

    If mine need to be “silver” just like an aluminum radiator I wouldn’t have either without matte or flat black. It’s a personal preference but I like everything behind the grille to be black.
     
  9. AngleDrive
    Joined: Mar 9, 2006
    Posts: 1,037

    AngleDrive
    ALLIANCE MEMBER
    from Florida

    Me too
     
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  10. TheSteamDoc
    Joined: Jul 14, 2018
    Posts: 281

    TheSteamDoc
    Member

    I'd definitely would recommend a light coat. After all, some are painted from the factory!
     
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  12. BJR
    Joined: Mar 11, 2005
    Posts: 7,530

    BJR
    Member

    This one is from Vintage Air, but came un painted.
     
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  14. ehdubya
    Joined: Aug 27, 2008
    Posts: 2,315

    ehdubya
    Member

    I believe black has traditionally been used because of its greater thermal efficiency than color.
     
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  15. nrgwizard
    Joined: Aug 18, 2006
    Posts: 1,648

    nrgwizard
    Member
    from Minn. uSA

    Just use actual radiator paint. It is thin, coats well, doesn't block heat transfer like "normal" paint. Put it on just enough to blacken radiator. You can get it too thick...
    Marcus...
     
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  16. JWL115C
    Joined: Jan 28, 2010
    Posts: 266

    JWL115C
    ALLIANCE MEMBER

    Recommend using a lacquer paint. It is thinner than enamel and will cover with a lighter coat. Black color has no affect on thermal efficiency as the sun does not shine there.
     
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  17. Boneyard51
    Joined: Dec 10, 2017
    Posts: 5,623

    Boneyard51
    Member

    Painting the condenser will change the cooling capacity of the condenser. But a light coat of paint shouldn’t reduce it enough to cause a problem, if it worked good before the paint job.






    Bones
     
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  18. I painted my old 1965 Ford pickup black with yellow,oranges and red flames, the grille, hood and the front fenders looked good but a friend that was a painted encouraged me to shoot a clear coat over the entire truck, I sprayed it and a few weeks after I finished getting the truck back together it started running hotter than a 4 balled tom car, I pulled the good radiator out and had the radiator shop hot vat it, re-installed it and it never ran hot again.

    The main thing to remember to keep the paint thin and not build it up. HRP
     
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  19. theHIGHLANDER
    Joined: Jun 3, 2005
    Posts: 8,640

    theHIGHLANDER
    Member

    What color is an air cooled motorcycle engine? Yeah, low gloss black. @Blues4U beat me to it but a satin or semi flat black finish does indeed shed more heat. Don't overthink it. Clean it the best you can and rattle it with good ol Krylon Semi-Flat black. Best "make it go away" rattle can in the game. Not like you'll feel a difference, maybe the compressor will be less worked, hard to say.
     
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  20. hotrodjack33
    Joined: Aug 19, 2019
    Posts: 3,550

    hotrodjack33
    ALLIANCE MEMBER

    Anything except spray bedliner or undercoating should work fine;):p
     
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  21. gimpyshotrods
    Joined: May 20, 2009
    Posts: 20,242

    gimpyshotrods
    ALLIANCE MEMBER

    I hope not. Mine came painted from the factory!
     
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  22. error404
    Joined: Dec 11, 2012
    Posts: 345

    error404
    Member
    from CA

    I remember seeing a youtube video a while back where someone was testing temperatures of an intercooler unpainted versus painted. I believe the results of that test showed that the painted version actually lowered the temperature by a bit.
     
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  23. hepme
    Joined: Feb 1, 2021
    Posts: 211

    hepme
    Member

    did mine (less than 1/2) for only the part that showed with flat black rattle can enamel. No loss at all, flat black radiates the heat, not absorb it.
     
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  24. Oldiesmiles
    Joined: Jan 24, 2022
    Posts: 19

    Oldiesmiles

    I used flat black header paint, on the front face of rad. Worked just fine.
     
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  25. JWL115C
    Joined: Jan 28, 2010
    Posts: 266

    JWL115C
    ALLIANCE MEMBER

    Heat coming off does not care what color the part is. Heat coming in is more absorbed the darker the color. Touch a dark colored car that has been sitting in the sun and then touch a light colored car that has been sitting in the sun. The difference is remarkable.
     
  26. Ebbsspeed
    Joined: Nov 11, 2005
    Posts: 5,810

    Ebbsspeed
    ALLIANCE MEMBER

    The majority are not black, but bare aluminum, or aluminum colored paint.
     
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  27. Boneyard51
    Joined: Dec 10, 2017
    Posts: 5,623

    Boneyard51
    Member

    I was going to mention that! Glad you did. Like you said, you go out into the sunlight and touch a black car vs a white car, very noticeable difference! Might even burn your hand!
    Do the same at midnight, you can’t tell a difference in temperature.
    Or at least , that has been my experience.






    Bones
     
  28. Rolleiflex
    Joined: Oct 25, 2007
    Posts: 1,131

    Rolleiflex
    Member

    I echo what everyone else said about effectiveness.
    The ac condenser on my OT Jeep is black and came that way from the factory.
     
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  29. lippy
    Joined: Sep 27, 2006
    Posts: 6,164

    lippy
    Member
    from Ks

  30. Blues4U
    Joined: Oct 1, 2015
    Posts: 6,627

    Blues4U
    Member
    from So Cal

    You guys are wrong, color absolutely effects the heat transfer properties of a surface, this is pretty basic heat transfer stuff, you should know it already. Did you cut class that day in school?
    http://www.hk-phy.org/contextual/heat/hea/radia02_e.html
    Also:
    http://physics.bu.edu/~redner/211-sp06/class23/class23_transfer.html
     
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