To paint, or not paint radiator...performance test

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73 Mustang Convertible
Born an I-6, spent the teenage, 20 and 30 years as a 302, but at 40 will reach full potential as a 351C.
Either this evening or tomorrow, I will comparatively test whether a non painted radiator is more efficient at cooling water than a non painted radiator.

Due to unfortunate circumstances, I have 2 modern radiators(non Mustang, but I don't think that matters), meaning plastic top and bottom, aluminum core, 2 core I think. One is painted black, the other is not. Otherwise these are identical...at least they weigh the same.

I intend to perform the following:

Experiment: Comparison of NON Painted Aluminum Radiator Core Performance to an identical Black Painted Aluminum Radiator Core

Hypothesis: Black paint, which may serve as a slight insulator to the thermo-conductivity of a radiator, will, when properly applied to an aluminum radiator core, increase the efficiency of the core and provide a greater cooling capacity than a non-painted aluminum radiator. The reasoning is the black paint will help draw out the infrared energy emitted from the water housed in the radiator. This energy can then be transferred to the cooler ambient air.

Material:

1 Unpainted Aluminum Core Radiator

1 Black Painted Aluminum Core Radiator

Boiling Water(amount to be determined)

Meat Thermometer

Shot Glass(capacity to be determined)

Knot Irish Whiskey(amount to be determined)

Procedure:

1. I chose night to increase the delta between ambient air temperature and radiator temperature. This should in turn decrease the time required for the radiators to cool the water.

2. The radiators, sitting outside adjacent to each other, straddling 2 wooden benches 16" off the ground, will be filled with equivalent quantities of water. Water to be prepared to 212 degrees/100 centigrade, 57' above sea level.

3. Water will NOT be circulated. I can't do everything.

4. Temperature will be measured with my wife's newest meat thermometer(mother's day gift) as it is most likely to yield the highest accuracy. (I have to be careful as she now knows when I am measuring temperature, I promptly seek out one of her tools...but she it out tonight!!!) The accuracy of the thermometer will be tested by placing it in boiling water on the high side, and a glass of Knot Irish Whiskey on ice for the low side.

5. Ambient temperature(air around the radiators) and radiator exterior temperature measurements will be taken between shot's of Knot 100 proof Irish whiskey...so every 10 minutes or so...at no less then 6 locations on each radiator. Temperature of the Knot whiskey will not be taken as this information is irrelevant to the test...but it will most likely be 32 degrees/0 centigrade as I chill it on ice. Oh, what the heck. I will measure the temperature of the whiskey.

6. Once a clear winner has been established, the radiators will be emptied and a second test will be done to confirm the results of the first test. To assure consistency between tests, the equivalent amounts of water in the first test will be used. However, I may rotate through several shot glasses so the amount of Knot Irish Whiskey in any one shot may vary.

7. Results will be posted here so the wise guys can ignore them.

Should anyone reading this post determine there are additional parameters I need to take into account, or any other issues which would provide a more accurate/reliable test, I am open for suggestions.

I would include the table, but it's a mess on the web site.

 
Black absorbs heat. White reflects it. That's why it's a bad idea to paint your rear brake drums black.

 
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Black absorbs heat. White reflects it. That's why it's a bad idea to paint your rear brake drums black.
I don't mean to start anything but this is a misconception. While black absorbs heat more quickly than white it also dissipates this heat faster. So my guess is that the black will out perform the unpainted, it may be slight but it will be there. Are you planing on giving each the same amount of airflow?

This is a more complex version of a simple physics experiment.

 
The operating temperature of the engine determines the efficiency of the radiator more so than the radiant or ambient heat heat readings from the actual radiator, it's job is to dissipate heat so it should be hot. What difference paint plays will be interesting...fun stuff.

Jim

 
Are you planing on giving each the same amount of airflow?

This is a more complex version of a simple physics experiment.
Of course...I believe you will enjoy my method of measuring air flow...



Black absorbs heat. White reflects it. That's why it's a bad idea to paint your rear brake drums black.
I don't mean to start anything but this is a misconception....
I was unable to find anything on the internet that duplicates what I am doing. The only experiment I remember regarding this concept was the old metal flag on a pin post in a vacuum tube device, where one side of the flag was white, and the other black. If I am not mistaken, the light PUSHED on the white side and pulled on the black side...not that there is anything wrong with that.

 
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Of course...I believe you will enjoy my method of measuring air flow...
Now I'm curious...

I was unable to find anything on the internet that duplicates what I am doing. The only experiment I remember regarding this concept was the old metal flag on a pin post in a vacuum tube device, where one side of the flag was white, and the other black. If I am not mistaken, the light PUSHED on the white side and pulled on the black side...not that there is anything wrong with that.
The experiment I'm referring to is this:

You take three identical soup cans, paint one black, one white and leave the other unpainted and shinny. (The cans are painted inside as well) Put the same amount of water into each and place them under a heating lamp leaving a enough distance so they do not absorb each others heat. (Make sure they all get ample amount of heat) Place a thermometer into each and observe the changes in temperature. Then turn off the heat lamp and observe the temperature changes. Record these and graph the temperatures over time.

After doing this experiment you should find that the black can increases and decreases in heat the quickest, then white second, and shiny last. If you leave them under the lamp long enough they will all reach the same temperature.

 
You take three identical soup cans, paint one black, one white and leave the other unpainted and shinny. (The cans are painted inside as well)
The reason this experiment does not apply to us is we are unable to paint the inside of our radiators.

 
Give this a read if you want to know why. I've also copied it below.

http://www.offroaders.com/tech/paint-it-black.htm

It's been said that black is actually the best color for dissipating heat from the engine. This statement is true, here's why:

The reason black paint dissipates heat more than any other color is that black is the most capably dissipative color for infra-red (heat) wavelengths. As we all know, back is very absorbent when energy rays (visible AND invisible) such as sunlight hit it. It is also able to cast off the most heat energy, all of its radiation being in the infra-red part of the energy wavelength spectrum. Single colors tend to focus their ability to both absorb AND dissipate in the wavelength of their color, and far less in the infra-red compared to black. One last thing about black: It absorbs energy better than it dissipates it, which is likely why the effect of black dissipating heat is less known. Also, since it absorbs far better than it dissipates (as do all colors), it has a net gain, for example when your black car sits in the sun, until an equilibrium is reached depending on the heated body's ability to be cooled (like with a fender or hood, by the surrounding air). The ambient temperature of the air around the black fender keeps it from heating beyond a certain range. I hope this helps explain the "I don't know why" of black paint being a better cooler for engines. The effect won't be much, and might not even be noticeable unless closely monitored, but it is a fact.

Black radiates heat in the infra-red spectrum better than other colors, which tend to "specialize" by radiating less efficiently in the infra-red and more in just their color portion of the spectrum.

Speakers analogy: With regard to black being able to radiate heat well, heat is like a bass note, black is a woofer, and other colors are "mere" tweeters.



You take three identical soup cans, paint one black, one white and leave the other unpainted and shinny. (The cans are painted inside as well)
The reason this experiment does not apply to us is we are unable to paint the inside of our radiators.
Radiators are sealed and in this experiment this is only necessary because the inside is exposed. To be honest it doesn't matter in the experiment either, the effects are slight to negligible.

 
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You must type like a banchee...not sure exactly what a banchee is, but it is in reference to something that is astonishingly quick.

 
You must type like a banchee...not sure exactly what a banchee is, but it is in reference to something that is astonishingly quick.
I don't type that fast and in fact I don't type the proper way.

Anyhow this should still be an interesting experiment because of the direct way of testing the relationship color has on radiators. I think that there might be too many variables but still pretty scientific.


Also, I didn't mean to take over your thread in any way.

 
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Also, I didn't mean to take over your thread in any way.
The thought never occurred to me.



Also, I didn't mean to take over your thread in any way.
The thought never occurred to me(like I have never taken over a thread).
 
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Black is only black if there is light to see it. The test must be conducted in daylight to be truly valid. Bare aluminum is my choice for performance, not because black does not dissipate heat, but because a paint coating does act as an insulator. Paint one clear and one black for for an apple to apple comparison.

 
What a great thread! James, as a former peer-reviewed researcher/author-turned high school science teacher, you get an A++ in Scientific Method. The Knob Whiskey portion was sheer genius.

If you publish the results here and they indicate that the painted radiator is more efficient, I reserve the right to ignore the results since I just installed a new Summit aluminum radiator last week, and I refuse to once again drain it, disconnect the hoses, etc. etc. at this time. Down the road perhaps.

If you're interested in pediatric allergy/immunology and possible "cures" for asthma that involve blood cell components, Google "Histamine Release Inhibitor Factor" along with "Rafael Alam" and maybe "University of Texas Medical Branch" for good measure. I co-authored several articles with Rafael, including one in the Journal of Immunology.

 
I was waiting for you to jump in Doc. That's cool to hear you co-authored articles about allergy/immunology.

 
I was waiting for you to jump in Doc. That's cool to hear you co-authored articles about allergy/immunology.
Ya, I don't usually toot my horn but it was something that I'm proud of that I did when I was young(er). Most of the articles that are available online are pretty dry and use a lot of complex/boring terminology, but there was certainly an excitement of "exploring the unknown" back then in 1987 - 1989, and we were young and thought we were helping to find the cure for asthma and allergies in kids. What a fun, fulfilling time that was!

 
What a great thread! James, as a former peer-reviewed researcher/author-turned high school science teacher, you get an A++ in Scientific Method. The Knob Whiskey portion was sheer genius.
Nothing but the best for 7173mustangs.com.

If you publish the results here and they indicate that the painted radiator is more efficient, I reserve the right to ignore the results since I just installed a new Summit aluminum radiator last week...
Good Timing!!! But, I seriously doubt anyone blew up a motor by either painting or not painting their radiator.

If you're interested in pediatric allergy/immunology and possible "cures" for asthma that involve blood cell components, Google "Histamine Release Inhibitor Factor" along with "Rafael Alam" and maybe "University of Texas Medical Branch" for good measure. I co-authored several articles with Rafael, including one in the Journal of Immunology.
Outstanding!!! Cannot wait to read it...honestly.

 
Give this a read if you want to know why. I've also copied it below.

http://www.offroaders.com/tech/paint-it-black.htm

It's been said that black is actually the best color for dissipating heat from the engine. This statement is true, here's why:

The reason black paint dissipates heat more than any other color is that black is the most capably dissipative color for infra-red (heat) wavelengths. As we all know, back is very absorbent when energy rays (visible AND invisible) such as sunlight hit it. It is also able to cast off the most heat energy, all of its radiation being in the infra-red part of the energy wavelength spectrum. Single colors tend to focus their ability to both absorb AND dissipate in the wavelength of their color, and far less in the infra-red compared to black. One last thing about black: It absorbs energy better than it dissipates it, which is likely why the effect of black dissipating heat is less known. Also, since it absorbs far better than it dissipates (as do all colors), it has a net gain, for example when your black car sits in the sun, until an equilibrium is reached depending on the heated body's ability to be cooled (like with a fender or hood, by the surrounding air). The ambient temperature of the air around the black fender keeps it from heating beyond a certain range. I hope this helps explain the "I don't know why" of black paint being a better cooler for engines. The effect won't be much, and might not even be noticeable unless closely monitored, but it is a fact.

Black radiates heat in the infra-red spectrum better than other colors, which tend to "specialize" by radiating less efficiently in the infra-red and more in just their color portion of the spectrum.

Speakers analogy: With regard to black being able to radiate heat well, heat is like a bass note, black is a woofer, and other colors are "mere" tweeters.



You take three identical soup cans, paint one black, one white and leave the other unpainted and shinny. (The cans are painted inside as well)
The reason this experiment does not apply to us is we are unable to paint the inside of our radiators.
Radiators are sealed and in this experiment this is only necessary because the inside is exposed. To be honest it doesn't matter in the experiment either, the effects are slight to negligible.
That being said, I think we're missing the point. At 32 deg water goes from liquid to solid. At 212 deg it goes from solid to gas. At what temp does black (depending on the paint type and metal covered) start dissapating heat instead of absorbing?) Hmmmm.

 
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