"Bill Daniels" bildan@comcast-dot-net wrote in
:


"john smith" wrote in message
...
Bill Daniels wrote:
The following is from Bellcore. The first number is the solar
energy absorbed the second is the low temperature heat radiation.
As you can see, polished alumunum absorbs only slightly more than
white paint but radiates only 6% as much heat. In other words,
although it absorbs little, it radiates much less so it heats up
more than any painted surface.

Polished Aluminum .15 .06

White .14 .97

Yellow .30 .95

Cream .25 .95

Light Grey, Green Blue .50 .87

Med. Grey, Green Blue .75 .95

Dark Grey, Green Blue .95 .95

Black .97 .96

Hmm?
You think this may be why so many airplanes are mostly white?

It is absolutely why composite aircraft structures are white. My
white carbon/glass composite glider has a structure thermometer. The
POH states the maximun structure temperature at which a flight can
begin.

The next time you have a chance to look at some old cars, compare the
white ones to, say, red ones. White paint seems to last forever.
White paint reduces air conditioning requirements and in turn
increases gas milage.

Bill Daniels



But the red cars go faster. At least the police seem to think so.