Panel radiator colours

[sigma]

Why are domestic panel radiators painted white, surely black or a dark colour would be more thermally efficient.

[ChuckFickens]

only by a very tiny bit, for a start most radiators don't actually radiate most of the heat you get from them, they work more as convection heaters, but that aside, the emissivity and absorptivity of black and white when dealing with heat (fairly long wave radiation) is virtually identical. and more difference will be seen due to the surface texture over colour. a matt white radiator would be more effective then a gloss black one.

[sigma]

Sorry docspock but I disagree with your answer, yes anything hot will radiate heat but the colour or texture will affect the amount of heat radiated, that's why the linings of vacuum flasks are white and chrome.The combination of vacuum, chrome and white surfaces retain as much heat as possible

[Toureman]

I agree with the Doc.

Just paint it if you want another colour..

[weeal]

check these out
http://www.designer-radiators.com/acatalog/Col oured.html

yumm

[rccatnap]

An ideal radiator is a matt black sphere in a vacuum. This would of course be impossible to replicate in one's home.
There would be a slight advantage in having black room radiators but it would indeed be very slight.
Having said that, I have painted the rear of mine matt black and glued a silver insulated reflector panel on the wall behind the radiator. The front is painted to blend with the decor.

[buildersmate]

Doc and Toureman are incorrect and have clearly forgotten any physics they learned. A good answer just above, I thought.

[sigma]

Cheers catnap,That sounds the right way to go.
Harking back to school physics, I can recall having a cube, each face painted either black/white, matt or gloss and measuring the thermal efficiency. Matt black having the highest thermal efficiency and gloss white the lowest.

[Jugglering]

I can remember being told by a guy who worked in a radiator factory that the *white* paint was actually intended to act as an undercoat and you were supposed to paint the radiator to match your dec�r... I have no idea if this was a wind-up but all my radiators are now painted (gloss, not emulsion).

[beso]

What Chuck said and:

The surface of most of the fins in a radiator face other fins. Radiation depends not only on the hot surface but also on the nature of the absorbing surface which in this case is a surface at the same temperature with identical radiation properties.

Colour isn't very relevant. The device is really a convection heater.

[ghoole]

Its simply aesthetics, there are many black, silver, red, blue even chrome plated etc radiators available.

See here for many examples http://www.designer-radiators.com