Dudeland 273 August 20, 2018 I would normally say it didn't matter what colour your rad or condenser is but take a look at the video below from MCM (mighty car mods) and tell me this wouldn't make a difference. I realize it is an intercooler but it is the same principle. Share this post Link to post Share on other sites
jimk 734 August 20, 2018 (edited) Everything has a radiation effect but the radiator transfers heat by convective cooling. If it were radiation was primary, the color would affect the exhange rate. But it's a finned fan heat exchanger and it has been misnamed forever. So don't wasted the paint. This is physics 101. Edited August 20, 2018 by jimk 1 Share this post Link to post Share on other sites
Dudeland 273 August 20, 2018 I am thinking that the radiative effect is most important when air flow is low in stop and go traffic. The heat lost through convection will not change but the radiant heat would if the rad gets painted. Sent from my iPhone using Tapatalk Share this post Link to post Share on other sites
SteveJ 178 August 20, 2018 Using the wrong (thick) paint will reduce air flow. There is a thinner spray paint available just for radiators....err....heat exchangers.🙂 Share this post Link to post Share on other sites
jimk 734 August 20, 2018 Adding paint adds insulation to the heat exhange surfaces. Have you deducted this effect from the radiation gain and convective properties? Share this post Link to post Share on other sites
AustrianVespaGuy 250 3 Vehicles August 20, 2018 I'm an engineer at a radiator company and our plant primarily manufactures radiators and intercoolers for tractor-trailer trucks. We paint some customers cooling modules (radiator + intercooler + HVAC condenser) black for aesthetic purposes and some we do not. For the projects where paint is requested, we've tested coolers back to back in our wind tunnel (first unpainted, then painted), where we have a HIGHLY controlled environment (coolant temperature, pressure, flowrate, air flow temperature, pressure, flowrate, humidity, etc. over a complete range of operating conditions) and the difference in heat transfer is always less than the the noise of the system, which is just what the video here shows also (100 vs 97 degrees is certainly within the measurement error of that setup). While they are also correct that radiative transfer does increase with black paint, this actually doesn't matter in the real world, because there's *ALWAYS* airflow across the intercooler (radiator and/or condenser fans on, breeze, etc.) even when stopped, and the convective transfer so far outstrips the radiative that it becomes negligible. So actually a decent video with reasonable data, but the conclusions were still off a bit. Again some OEMs still pay for paint for aesthetics, like when you can see the heat exchanger through the grill, but that's it. Also true there isn't really a downside (convective transfer is not worsened) aside from cost, so take the OEM route and paint it if you like how that looks, but it won't affect performance at all. If you want better intercooler performance at peak torque when accelerating from a standstill with very little airflow, then you need a liquid-to-air intercooler, but this then requires a special low-temperature radiator to cool the coolant enough and you better darn well make sure it doesn't leak, because coolant dribbling into the intake tract can quickly spell hydrolock! 3 Share this post Link to post Share on other sites
kbmb02 770 August 20, 2018 (edited) 6 minutes ago, AustrianVespaGuy said: I'm an engineer at a radiator company and our plant primarily manufactures radiators and intercoolers for tractor-trailer trucks. .... and the difference in heat transfer is always less than the the noise of the system... Outstanding - I like real-world test data. -KB Edited August 20, 2018 by kbmb02 Share this post Link to post Share on other sites
jimk 734 August 20, 2018 (edited) 8 minutes ago, kbmb02 said: Outstanding - I like real-world test data. -KB You guys poured cold water on the subject. I wanted to see how far the hair splitting would go! Like I said, don't waste the paint. Edited August 20, 2018 by jimk 1 Share this post Link to post Share on other sites
John_in_VA 549 August 20, 2018 Eastwood sells satin & gloss black radiator paint, if you want to waste your $ & paint: https://www.eastwood.com/ew-radiator-black-12oz-satin-finish.html https://www.eastwood.com/ew-radiator-black-paint-gloss-aerosol-12-oz.html Share this post Link to post Share on other sites
reyes02 35 August 21, 2018 I can see the insulation point of view. However with additional paint wouldn’t it create slightly larger fins? I’d assume the larger the fin would absorb more air, causing better cooling. while moving of course I agree in traffic it’d probably not be a good idea. Anyways they look cooler black gives it a more stock look rather than having some chrome shining out from under the bumper/grills. Share this post Link to post Share on other sites
John_in_VA 549 August 21, 2018 An original radiator looks cool with polished brass tanks, too. 2 Share this post Link to post Share on other sites
Dudeland 273 August 21, 2018 So here is my answer. Only time will tell if I am right. Share this post Link to post Share on other sites
jimk 734 August 21, 2018 21 minutes ago, Dudeland said: Only time will tell if I am right. I don't recall seeing in this thread where there was a problem before. Share this post Link to post Share on other sites
John_in_VA 549 August 21, 2018 59 minutes ago, Dudeland said: So here is my answer. Only time will tell if I am right. Overspray, just like from the factory! ( ; p) Share this post Link to post Share on other sites
Conserv 2,433 August 21, 2018 All fine, but if the color of the radiator and condenser on your ‘02 means the difference between overheating and not overheating, I’d suspect you have more substantive cooling system issues than the choice of color.... 😉 Regards, Steve Share this post Link to post Share on other sites