I need help please

[mwinjuma]

Hi to all of you
Actually I need help please about this question.The question was as:
Compressor is black in colour in order to absorb heat easily.Why it needs to absorb heat rather than to reflects heat?

Only I know that if compressor absorb heat it will gain the heat and it becomes so hot.So it tends to trip the overload(internal or external overload) so it will stops to work properly and the performance will be bad.So why the question is asked like this

[chillin out]

You will probably find the reason it is black in colour is that it is a cheap (not expensive) colour and it also hides the dirt well.

Imagine if it were white, we would have to spend a lot of time getting our dirty finger prints off them. Black hides a multitude of sins.

Chillin

[powell]

I found this interesting article about car engines and painting them black to run cooler.

Check it out.

www.sacskyranch.com/paint.htm

[Gwyn]

Some overhaul shops claim beneficial cooling effects of black paint on their engine. The theory is that black is a better emitter of infrared (heat) energy. A hot engine in a cold surrounding, radiates energy from the hot object to the cold. The amount of radiant cooling is (generally) dependent upon the temperature of the emitter (engine) and how efficient the engine is at radiating energy -- its emissivity. This derives from Kirchoff's Law where good absorbers are also good emitters. Since black is a good absorber of energy (that's why it's black) it's also a good emitter. A black object emits more radiant energy (cools faster) than a white or gold object that emits less radiant energy per unit of time. Painting an engine black increases the amount of radiant energy emitted by the hot engine to its colder surroundings and it will be cooler than a non-black engine.

Got it now!

[daddyfixit]

Way cool.... and I thought it was the cheapest paint too. Learned something new again...

Thanks


Wish you the best....

[Chris Ellison]

Just think what color most heatsinks on electronic devices are. A lovely shade of black. As already said a good aborber of heat is also a good radiator.

[Victorman]

mwinjuma :

The radiant heat transfer in a blackbody is proportional to the fourth power of the absolute temperature .

Victorman

[brianubaldo]

mwinjuma

most of compressors are colored black.. but some are green like sanyo compressors.. my advice is you should check it to the manufacturer why did they put it. just search in the net.

_______________________________________________
brian
SAMSUNG Tech. Support

[nike123]

mwinjuma

most of compressors are colored black.. but some are green like sanyo compressors.. my advice is you should check it to the manufacturer why did they put it. just search in the net.

_______________________________________________
brian
SAMSUNG Tech. Support

Most of the Sanyo compressors are rotary type cooled by suction gas.

[Greengrocer]

Some overhaul shops claim beneficial cooling effects of black paint on their engine. The theory is that black is a better emitter of infrared (heat) energy. A hot engine in a cold surrounding, radiates energy from the hot object to the cold. The amount of radiant cooling is (generally) dependent upon the temperature of the emitter (engine) and how efficient the engine is at radiating energy -- its emissivity. This derives from Kirchoff's Law where good absorbers are also good emitters. Since black is a good absorber of energy (that's why it's black) it's also a good emitter. A black object emits more radiant energy (cools faster) than a white or gold object that emits less radiant energy per unit of time. Painting an engine black increases the amount of radiant energy emitted by the hot engine to its colder surroundings and it will be cooler than a non-black engine.

Got it now!

Probably the same reason most of the old A/cooled condensers on Presold / Fridgidaire cond units were sprayed matt black. In fact the whole dam unit was black. Funny but I can't remember seeing many black condensers these days. Most are either bare Cu tupe /Ali fin or are Ali coated with other finishes to prevent corrosion e.g. Blue, Gold etc.

[powell]

I'm showing my age, I remember when the Copeland condensing unit condensors were steel finned, painted black and had a wide FPI.

[swaminathan van]

hi all, i had seen a lot of manurop compressors and they were a shiny dark blue and they ran quite well.

[US Iceman]

Look at the radiators on cars and trucks. They are black. I suspect some companies use a specific color because it helps to provide brand recognition and has nothing to do with heat rejection or absorption.

[nike123]

Heat rejection, on large compressors, thru housing is to small, and they are cooled by suction gas (or cooling of oil in separate oil cooler). So, on large compressors color has nothing to do with heat rejection except it could help a little, but not much.
On the other hand, small compressors, like in refrigerators, are mainly cooled by housing and therefore they are always painted black because black color helps in rejecting heat.

[monkey spanners]

Those old Prestcold compressors used to be green 1960's, then light blue 1970's and then black 1980's all with the same basic compressor design but with different condensers.
And those old yorkamatic units used to be green....

Oh i'm off down memory lane

All the modern stuff seems to be powder coated, which peels off after a few years.

Jon