The benefits of painting intercoolers black

[andone89]

https://www.youtube.com/watch?v=f1QL9veQaNg
Can someone confrim this for me?
Small things make all the difference

[olefud]

https://www.youtube.com/watch?v=f1QL9veQaNg
Can someone confrim this for me?
Small things make all the difference

It makes qualitative sense. Radiant cooling is driven by the emissivity –black body is unity- and the fourth power of the absolute, i.e. relative to absolute zero, of the emitting surface and what that surface “sees”. With air flow over the surface the emitting temperature is lower and the black surface makes less difference. A nice feature of radiant cooling is that the hotter the emitting surface, and accordingly the more cooling is needed, the greater the radiant cooling contribution.

I used to paint my oil pan silver on the side that saw the exhaust header and black on the other side.

[timbo]

In this day and age I wonder if teams are starting using more of those nano-material coatings. A meta-materials with tuned spacing between nanometer-scale surface features may have remarkably high efficiency reflecting certain wavelengths. Same probably applies to radiation.

[proteus]

The black colour radiates heat the best way possible. I remember the saying back in the highschool at physics, when the teacher told us that in the summer on the sun we need to be dressed white, while in the shadow we need to be dressed in black, so we would be feeling as cool as possible

[bdr529]

I not quit sure it's the best thing to do, for a few reasons

1) the black intercooler performed best when no air was moving over it (car stopped), because the black colour was able to radiate that heat out into the atmosphere (the garage), but inside the engine bay the temperature difference between the intercooler and the engine bay is going to far less then out in the open like the garage, the colour black also as the ability to absorb heat and if the air temp. around the intercooler is greater then in inside, it will not radiated heat but absorb it instead.

2) the non-painted intercooler did best when air was moving over it (car moving) by 3 deg. but seeing as you spend more time moving then at a stop I would think the non-painted intercooler is the way to go

3) painting the intercooler is just going to make the air ways smaller and if you F**k it up and block off some of the air channels then you have defeated the purpose and made matter worse

If you see a car with a black intercooler it may be anodize aluminum and not painted

[piast9]

For sure black intercoolers will not hurt but isn't the radiation negligible small compared to the convection forced by the air flow in a car that travels at race speed?

[George-Jung]

The black colour radiates heat the best way possible. I remember the saying back in the highschool at physics, when the teacher told us that in the summer on the sun we need to be dressed white, while in the shadow we need to be dressed in black, so we would be feeling as cool as possible

Like cool as in temperature.. Or cool as in Johnny Bravo..

[bdr529]

For sure black intercoolers will not hurt but isn't the radiation negligible small compared to the convection forced by the air flow in a car that travels at race speed?

You noticed the same thing better performance at speed from the unpainted intercooler

[andone89]

Thank you all for your answers. I think that making a black intercooler but not to paint it black is a step in the right direction due to it not having major draw backs(Because when you have already black material and don't have to add that extra layer of black, which in my mind is the reason why the temperature change dropped by 3 degrees with air flow.) but huge gains when a car is stationary. In formula 1 cars rarely are stationary, I agree, but having a better cooling while the car is on the starting grid on in the pits can not be hurting or can it?

[rjsa]

Like yourself said, it is a good idea if the paint you're using is not a thermal insulator to get in the way of the convection heat exchange.

[bdr529]

Thank you all for your answers. I think that making a black intercooler but not to paint it black is a step in the right direction due to it not having major draw backs(Because when you have already black material and don't have to add that extra layer of black, which in my mind is the reason why the temperature change dropped by 3 degrees with air flow.) but huge gains when a car is stationary. In formula 1 cars rarely are stationary, I agree, but having a better cooling while the car is on the starting grid on in the pits can not be hurting or can it?

The huge gains when the car is stationary are only because the test was done on a work bench and not in the engine bay
the temperature in the guys garage would be in the 20's Celsius range not the same as being in the engine bay.
In the test they used a hair dryer which would have moved more hot air though the intercooler faster then the turbo would have on it own while a car is stationary

A strange but functional example would be: take 3 trays of baked cookies out of the oven put 1 on the counter, 1 in the fridge and the last 1 in the freezer I'm sure you will find that the cooling rate of each of these cookies is not the same

When the car is stationary you need to cool the radiator fluid that's why there is an electric auxiliary fan on the radiator to help this
you don't need to cool the intercooler because the turbo is not really adding any power when the car is stationary, it's not till you start moving that the turbo starts to work and by then you are already passing cool air over the intercooler

Don't forget your not just painting it black you first have to apply a coat of etching primer because paint wont stick to aluminum then paint it black, by the time your finished you've add another 1-3mm to each of the fins, which means you'v closed off each of those air channels by 2-6mm, You add that up over the whole of the intercooler and you will see that you've decreased it's over all performance by a few %.
Any part of the intercooler that doesn't get touched by the etching primer will not accept the high heat black paint and that will eventual peel off and start to block off the air channel

20 plus years in the coating industry tells me that this could cause more trouble then it's worth

[strad]

All I can say is that years ago Triumph found that flat black (actually lamp black) was best for painting the cylinders of motorcycles with regard to cooling.

[bdr529]

They still paint them black on their air cooled bikes, but on a bike the cooling fines have larger spacing between them then a intercooler,
I'd have no problem if the factory painted them, at lest they would use a better coating that had a lower viscosity, then the one the general public could buy from a hardware store, your not going to get the best possible job from using a couple of spray bombs,
The guys in the video used forced air to help the paint move though the channel, but that will also start drying the primer/paint quicker and may start to clog up the air channels.
There are just to many places where the paint is going to build up and start to block the air movement though it
My professional opinion: This is not a DIY project, Buy one that is factory painted or get someone to anodized it in black