Quote:
Originally Posted by jb66
Well whites more reflective so It won't absorb as much heat, I guess it's why folk who live near the desert wear white clothes and tesco refrigerator lorries are white
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Well, with clothing many wear black in hot and desert countries. In tests, neither black nor white nor any other light or dark colour made a difference. For clothing. Not to heat retention nor reflection. To reflect (or indeed to insulate by reflecting back in) the material has to be silvered like those mylar sheets marathon runners use after a race. If white did reflect heat like silvered material does then it would insulate internally radiated heat as well as shield against external sources of course. It doesn't though. The idea that white or light is more reflective is a myth. The idea that black or dark absorbs more heat is a myth.
We are talking radiated heat here of course.
Colour shouldn't make a difference with anything else either (such as cabs), where radiated heat is concerned. Other varient qualities in the paint might make a difference to conducted or convected heat though. Any varience in cabinet construction across those tested would also play a part as would location and heat generation levels inside the cabs.
Remember, colour is only about our perception. It doesn't actually exist as an innate property of an object.
What the material needs to reflect here is infra-red.
If black were to absorb more heat, it would actually keep that heat from being released into the cab. If it reached capacity then it would be radiating heat instead. This is what we are suggesting white does though. If white reflected then it would insulate the cab by radiating heat in both directions. If there is a difference in how these colours react to infra-red then it's balancing out pretty well. If this is the case then one has to measure the temp of the air inside the cab and not the surface temperature of the cab.
There is a lot to look in to, but I still maintain that the use of non metalic colour to insulate or protect against heat is a myth. A commonly held one though.