On Tue, 13 Jul 2010 22:51:39 -0400, LSMFT wrote:

There is a push to cool the earth, save energy and keep your home cooler
at less cost to have white roofs. Especially in the cities to reduce
heat islands.
What about northern states where we heat more than air condition. Should
we go to white roofs or black roofs or middle colors?

In Indianapolis for many years, there were two big department stores
downtown. Blocks and Ayres. The Blocks lived just doown the street
from us, on the nice part of the street, the really nice part, but we
drove by their enormous house to get home. Later, the son built a big
house next door, with dark shingles. Four months later, the shingles
were replaced with white or almost white. This was probably 1961.

My townhouse had dark brown shingles and when my next door neighbor
and I needed a new roof, I talked him into light brown. White
wouldn't have looked good. He uses his AC a lot and I rarely use
mine, and I think maybe I helped him more than me, becaues with the
cooler attic he saves money on his AC and I don't use mine enough to
save more than a bit of money. For me, in the summer, I'm pretty
sure the house is not as hot as it was. (Maybe I need more insulation
on part of the attic floor but most has plenty.)

But in the mid fall and early spring, I turned off the roof fan so the
attic got as hot as possible and I used the heat of the attic to warm
the house. That doesn't seem to work anymore. It was only good for
2 to 4 degrees but it was also the difference between closing the
windows and turning on the heat, versus leaving them open and heating
a little bit the house from attic.

All these effects would be a little greater with white. I was
afraid, warned even, that white would look dirty eventually, although
I don't know why he claimed that. I meant to look at other white roofs
to see if any looked dirty, but I forgot that until just now, and I
never did it.

I think I'd still get light colored shingles rather than dark, no
matter what my habits aare.