It's cold in Boston where I live, and I am going to buy shades for my
east-facing sliding glass doors and windows.  What kind of shades
would be most energy efficient (at a reasonable price- nothing super
exotic and expensive please)?  I was thinking about "honeycomb" shades
like by Hunter douglas. If they come in an automatic version, I can
program my computer to raise and lower them to let the sun in during
the day.  During the summer, I will just keep them closed except when
I want to see out.  In this case, should the back of the shades be
white or "blackout"?  My winter electricity bills are 2x of those in
the summer (electric heat), so I think that it my major concern.  The
shades and mounting bar have to be 2 inches thick or less. Thanks.

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Clarification of Question by depth-ga on 05 Dec 2005 08:10 PST

Ooops. Actually my windows face south. Not that it necessarily makes a
difference for this question.

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Clarification of Question by depth-ga on 06 Dec 2005 12:00 PST

Thanks for the comments.  In the summer it is obviously better to have
white or reflective.  But for the winter, is it better for the black
to trap the heat near the window where it can leak out again, or let a
translucent shade let some of the light into the house.  Hopefully I
can aviod that issue by opening the shades during the day, though that
ruins their insulating effect.  Basically, what's the best strategy
overall for the winter?

And manuka, when I finish insulating the universe I will tell you how it went!

If you're interested in blocking the sun, get the honeycomb shades
with mylar inserts.  For the summer, I'd think you'd want the outside
of the shade to be white, and the other side to be black.

We have these shades in our apartment and have west facing windows. 
They do not have mylar inserts, and even with the shades closed, in
the summer around late noon it's like the light of god in there.  In
fact we put up posterboard in the window to block the light.

Thanks for the comment.  I'm not so much interested in blocking the
light- just which color I should pick for energy efficiency.  In the
winter, I guess if I am goign to have the shades up during the day it
doesn't matter.  If I am going to leave them down, I'm not sure if
black or white would let more heat into the house.

Black will let more heat in.  Black things absorb light and get hotter.  

White things reflect light and stay cooler.  Think of the temperature
of black cars in the summer vs. white cars.  However, the honeycomb
shades without mylar let a ton of light in. They basically just
obscure the view of the inside.  If you want it to actually be cooler
you need to block the light.

Off topic, but I saw in the index a question on "Expansion of the
universe", followed by this one, as I was scanning down in something
of a hurry. Somehow my mind joined them together into "Most efficient
plan for insulating the universe", and all I could think was that it
seemed just a bit too ambitious...