Question about the absorption of heat based on color

[timeuser84]

Hello there all, long time. I am not sure where to ask this question so If I am in the wrong area of forum, I ask that the moderator or administrator move this thread to the correct one please.

Is it true that any clothes you wear depending on the color will absorb heat because its black? For example if you wear black socks, will the black socks absorb heat more because its black or a dark color?

 

[phinds]

Direct sunlight will tend to warm up dark clothes more than light colored clothes.

 

[Baluncore]

Is it true that any clothes you wear depending on the color will absorb heat because its black? For example if you wear black socks, will the black socks absorb heat more because its black or a dark color?

Three different parts of the spectrum need to be considered.
1. Ultraviolet, UV.
2. Visible light colour.
3. Infrared, heat, IR.

The colour of clothing you see, is the colour of the visible light that is reflected from the clothing. Visible light that is not reflected becomes heat in the cloth. Some of that is radiated, while some will warm the wearer.

The reflectivity of the cloth to IR and UV cannot be seen by our eyes, but any IR or UV absorbed, will also heat the cloth.

Black clothing will absorb visible light better, but black may also radiate IR better. Material thickness will act as an insulator between your body and the environment. At night, you may want to stay warm.

 

[sophiecentaur]

Hello there all, long time. I am not sure where to ask this question so If I am in the wrong area of forum, I ask that the moderator or administrator move this thread to the correct one please.

Is it true that any clothes you wear depending on the color will absorb heat because its black? For example if you wear black socks, will the black socks absorb heat more because its black or a dark color?

Absorptivity at any frequency will be the same as emissivity at the same frequency. That 'could' imply that the colour would make no difference but the solar spectrum is wider than the visible spectrum and what goes on beneath the surface is as important as just on the surface.

Three different parts of the spectrum need to be considered.

This could be very relevant and we would have no clue by just looking at the fabric colour. In a simple model, the white and black cloth would reach the same equilibrium temperature and feel the same to the wearer. Left in a vacuum under sunlight this would happen. However, heat energy can go both ways from the fabric so the above 'ideal' description won't apply and the actual heat energy available to warm up the skin under a shite shirt will be less so the equilibrium temperature of the body will be lower (we have cooling mechanisms to help that).

Black socks are largely out of the direct sunlight and they get IR radiated from inside your clothes and also heat transfer by convection and conduction (ditto, your underclothes) so, in very hot conditions, you may be better off with insulating underclothes - unless you are active when you actually need to lose heat. Loose clothing of any colour will allow sweat to do its work. . . . . and so it goes on.

 

[timeuser84]

This was more than enough knowledge, thank you for the quick responses.