Interesting video about intercoolers that could have Ecomodding applications
 

I don't know if any of you watch mighty car mods on YouTube but I saw this video yesterday
http://m.youtube.com/watch?v=f1QL9veQaNg

I watched it because I had not heard about painting your intercooler black so I just wanted to see what was up.

This is a summary of the video if you don't want to watch it.
Basically the idea is that black objects have better emissivity (I hope that's spelled right) and will transfer heat better but the questions were does it actually work and does adding the paint end up insulating instead or helping. The results ended up being that with air flow to cool the intercooler the black painted one was 3 degrees lower than the non painted one which is worse (not enough to make a difference though) HOWEVER without air flow to cool it from the fan the black painted one had an output temp that was about 40 degrees LOWER! That's good because it means when you're sitting still without air flow to cool the intercooler you can end up heat soaking it which is bad so the 40 degree improvement is great!

So I was thinking that since a radiator and intercooler work similarly to cool either the coolant or air, respectively, if you have a grille block that will allow much less air flow to cool the radiator painting it black could help considerably, especially in city traffic or in a jam on the freeway, to keep the engine from getting too hot. What do you all think?

radiators come painted black.....I thought?? my kia is black and the one I bought for the Q45 was black

Really? Cause mine isn't. Maybe it's only newer cars come that way?

Most newer ones I have seen, especially the plastic tank aluminum cores are unpainted. My 1997 Ranger is not painted. All of the old soldered together ones were painted.

regards
Mech

Found a similar video. I think the first verse of the song is "I see a radiator and I want it painted black".

www.youtube.com/watch?v=9BcJaUYE5Jw&feature=player_detailpage
FYI, my Acura TSX has unpainted aluminum for the radiator and AC condenser.

Bad mod - don't do it.
 

About 9:25 in the video they say that they gained 40C with no airflow and LOST 3C (100C drop without paint, only 97C drop with paint) with airflow.

This first condition that everyone seems so excited about - heatsoak with no airflow - would not occur. When the car is stopped the turbo is not on boost (except for maybe a second or two before you take off if you're drag racing) and is not compressing (and therefore heating) the air. The intake air flowing through the intercooler and into the engine is close to ambient, so no heatsoak for the intercooler. Also, if your intercooler is mounted in front of the radiator, the radiator fan will be drawing air through it periodically, so no heatsoak.

Almost all of the time when you are demanding boost from the turbo the car will be moving, so there will be airflow through the intercooler. But by painting it, you have lost 3C of cooling. Net result = negative effect on performance. You are spending time, effort and money to make your car worse.

For the radiator, you should not have a heatsoak condition either. When the coolant temp approaches the upper end of normal, the radiator fan will pull air through it. But if you have painted it, you have reduced its ability to bring down the temperature of the coolant. Again, a net loser. JMHO.

But if you have a grille block and there is little airflow then this would be useful.

Hmm, hmm, hmm,..

I wanna see it painted, painted black
Black as night, black as coal
I wanna see the sun blotted out from the sky
I wanna see it painted, painted, painted, painted black

Yeah!

Hmm, hmm, hmm...

Are you saying that you can increase the grillblock after painting the radiator to reduce cooling drag? The paint would help while you're at a dead stop with no airflow (radiator fan not on), but once you start moving the paint makes it harder to lose heat from the radiator. So now you need more airflow than without the paint, but you can't get it because the grillblock is bigger (smaller opening). So again, I say net loser.

But if you try it, please let us know how it turns out.

If the hood is closed and the grill is blocked, wouldnt the radiator I mean condenser be black anyway?

That's kinda what meant. But you wouldn't really end to increase it like say you have a grille block and a belly pan. You'll have very little air flow to the radiator with that kind of setup so if you can get some improvement it would help. This is a situation where you have to lose a little to gain a little (or a lot depending on how you look at it) when I look at it I see it this way, I lose a tiny amount cooling capability when you shouldn't have a problem cooling (moving/driving) to greatly improve cooling ability when you'll have a harder time (sitting still) but that may just be how I see it. The biggest difference I would think would be if it would keep the fan off a little bit longer it could improve your fuel economy in the city a little bit.

I know I won't try it for a little while until I have instrumentation too monitor everything.

So, what would painting it white do?

...negate the need for another "Paint It Black" video & song (wink,wink).

If it was exposed to the Sun it would reflect more heat then it absorbs or much less then Black in any regard , I assume it would radiate less of the intercoollers heat from its surface as well .?
It is strange that "color" can do this , Spooky if you do not understand the science of it & I don't at the moment :confused: could it be color has surface area ?

Mom once told me the shinier side of aluminum foil reflected more heat. A roommate said that sounded like wishful thinking.

A shadow cast from the hood is not the same as something painted black. Shadows are the result of blocking light, while black is the result of absorbing light.

That's right.

We understand that black absorbs the energy from light and gets hot. What we aren't accustomed to thinking about is that you can heat something that is black and emit light in the form of infrared radiation.

A wine glass that is given energy by striking it will vibrate and emit a chime. Reverse this process and play a noise at the same frequency as the wine glass, and you get vibrations in the glass.

Many energy systems are reversible, and only depend on which side of the process has greater energy. Electricity can drive a motor and put a vehicle in motion, or a vehicle in motion can drive a motor that produces electricity.

Don't use paint.

Anodizing - Wikipedia, the free encyclopedia

Paint between the fins is not of much use since any radiation emitted there is mostly just reabsorbed.

Agreed, anodizing would be ideal, but cost prohibitive of course for us. I also don't think it'll really matter in the end.

Anyway, what we're talking about is thermal radiation, one of the three forms of heat transfer:
1) conduction (heat moving through a material)
2) convection (heat altering the density of a gas/liquid and allowing it to move)
3) radiation

Radiation is harder to think about, but basically everything in the line of sight of an object radiates heat to or from it. Lets use for example, yourself. Where you are right now, you're radiating heat to and getting radiant heat from everything that is within the line of sight of your body. Anything that has a higher temperature than your skin radiates heat towards you, and everything that has a lower temperature than your skin you're radiating heat towards. This is the principle of radiant heated floors, or why you can feel heat from a bright light bulb from 20+ feet away (or heat from a really hot fire from far away).

So, basically if you paint your radiator black, it will emit more radiant heat. IE it will be more efficient without airflow as stated. However, the paint does add a layer of insulation, so when air is flowing over it, it is less efficient.

In the end, I doubt that you'd even notice a difference from painting or anodizing the radiator, but you can give it a try.

The ideal configuration would be black on all external surfaces, and unpainted fins internally.

Painting the engine black should help a very small amount too.

Funny how we call the cooling component on a vehicle the "radiator" when the primary method of heat removal is convection. Should it be called a convectorator instead? Perhaps convector?

Not only does the paint add a layer of insulation, but it narrows the gap between the fins, which reduces the amount of air that can move through the fins and absorb heat.

My experience in the world of computers has been that active cooling (convection) is far more effective than passive (radiation), and I assume it applies equally to cars. With as little as 1-2 cubic feet per minute of airflow (and a radiator fan is likely in the hundreds, if not thousands!), you're getting more cooling from convection than radiation. Even a slight breeze over your radiator is probably helping more than radiation.

Those black rubber hoses are now super-heat-transfer hoses.