JRS: In article ,
dated Sun, 11 Jun 2006 14:30:11 remote, seen in
news:uk.transport.london, mookie89 posted :

Marc Brett wrote:

Does painting the roof white help with inside temperatures? I've noticed
many
new buses have this feature.

PMFJI ~ I ran a large fleet of public school (yellow) buses in the States
for 30 years. When it became OK to paint the rooftops white, many studies
were conducted to see if it helped the temps. There were as many
conclusions as there were studies. The largest benefactor appeared to be
the white paint manufacturer. However, a semi-common thread amongst all the
studies I was aware of said that if three things were used in tandem, then
there may be up to a three degree drop in perceived temperature.

1. Roof painted white
2. Windows tinted to at least 28% reduction in light transmission
3. Air circulation via front and rear roof vents (air in front - exhaust
out rear)

UK buses are frequently double-deckers, and operate north of 50 deg N.

US school buses are AIUI single-deckers, and operate south of 50 deg N.

In our joint Summer, the Sun is at about 20 deg N.

Therefore, the effect of roof-colour should be substantially greater in
the US in comparison with here, both for roof/side area and roof/side
angle; though the difference will be diminished if school buses avoid
mid-day operation.

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