06-29-2014, 11:04 PM
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#11 (permalink)
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Master EcoModder
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Quote:
Originally Posted by Patrick
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.
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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.
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06-29-2014, 11:26 PM
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#12 (permalink)
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Not Doug
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So, what would painting it white do?
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06-29-2014, 11:38 PM
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#13 (permalink)
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Quote:
Originally Posted by Xist
So, what would painting it white do?
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...negate the need for another "Paint It Black" video & song (wink,wink).
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06-30-2014, 01:04 AM
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#14 (permalink)
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Drive less save more
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Quote:
Originally Posted by Xist
So, what would painting it white do?
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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](/forum/images/smilies/confused.gif) could it be color has surface area ?
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06-30-2014, 01:48 AM
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#15 (permalink)
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Not Doug
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Mom once told me the shinier side of aluminum foil reflected more heat. A roommate said that sounded like wishful thinking.
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06-30-2014, 03:34 AM
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#16 (permalink)
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Human Environmentalist
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Quote:
Originally Posted by Cobb
If the hood is closed and the grill is blocked, wouldnt the radiator I mean condenser be black anyway?
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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.
Quote:
Originally Posted by ecomodded
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](/forum/images/smilies/confused.gif) could it be color has surface area ?
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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.
Last edited by redpoint5; 06-30-2014 at 02:12 PM..
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06-30-2014, 09:36 AM
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#17 (permalink)
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06-30-2014, 10:05 AM
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#18 (permalink)
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Paint between the fins is not of much use since any radiation emitted there is mostly just reabsorbed.
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06-30-2014, 10:06 AM
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#19 (permalink)
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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.
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06-30-2014, 02:22 PM
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#20 (permalink)
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Human Environmentalist
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Quote:
Originally Posted by jakobnev
Paint between the fins is not of much use since any radiation emitted there is mostly just reabsorbed.
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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.
Quote:
Originally Posted by Daox
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
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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?
Quote:
However, the paint does add a layer of insulation, so when air is flowing over it, it is less efficient.
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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.
Last edited by redpoint5; 06-30-2014 at 06:04 PM..
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