Doug's Reflectix Rollup Window Shades

These insulating window shades made from Reflectix insulation were described on a post to the Yahoo Solar Heat Group.

One inch dowel and half inch conduit

Window shade side track

Overview

These are the posts describing the shade from the Solar Heat Yahoo Group:

I made thermal night time
insulated shades, for about $15 each for my 34"x 76" windows.
They provide the "One way valve" to heat flow. I used
"Reflectix" -a double bubble pack, with Mylar facing on both side. It
claims R 10 with an air space. I made simple rollers to roll them up during the
day, each winter morning I just pull a cord to raise them, and pull them
down at night. They slide in grooves in the window molding to make for an
efficient seal.

Further explanation:
My shades are made using "Reflectix", a double bubble pack, with Mylar
facing on both sides. It is available at most home centers. I used spray
adhesive to cover the inside with muslin, an inexpensive strong cloth
available anywhere material is sold. Covering the Mylar with cloth probably
reduces it`s ability to reflect radiant heat somewhat, but the improved
looks are worth the tradeoff, IMHO. No sewing involved, and the shades cost
me about $15 for each of my 34"x 76"  windows, about 15 years ago. The only
maintenance I have done in that time is to replace the hardware, the usual
lightweight roller shade hardware only lasts for a few years. Maybe you can
find a source for stronger hardware, if you do please let me know. I have
taken to making my own.
  There are no horizontal battens, the Reflectix just looks that way after
it's rolled up and down a few times. It does look good. After a decade or so
of sliding up and down in the wood grooves, the edges of the shade wear
some, so I just folded a strip of white duct tape along both edges. This
also helps to make a good seal. I cut a small piece of the Reflectix to
attach to the top, it hangs down to so that it's lower edge rides on the
shade as it makes the corner around the smaller roller. I originally had
adhered cloth to the outside of the shade, but sunlight eventually caused
the adhesive to let go, I now leave the outside uncovered Reflectix, it
shows little signs of deteriorating after more than 15 years in place. It is
reflective enough that it helps to keep the space between the shade and
glazing from overheating if you leave the shade down when it`s sunny, but I
try to not do that. The "tracks" are just strips of poplar I cut from my
property, air dried, and planed. Any 3/4" wood will do, I made mine do
double duty as stop strips for the glazing and dadoed grooves in them for
the shade tracks. I attached a 3/4" x3/4" dadoed piece to the bottom of the
shade to give me a handle to pull the shade down with, and to help it seal
at the bottom. The rock on the cord is to keep the rolled up shade rolled
tightly, any weight will do, the stone just fits in with my stone house.
I`m glad to help, ask if you have any further questions. Sundug

Doug K. (who designed and built these shades) is happy to answer questions -- his
email address is:  sunart at netease.net --

Comment on R value:
I think that the R10 mentioned above is too high. As near as I can tell from the Reflectix site, they actually claim "R value of 4.5 from the Reflectix and both associated air films".

The Shurcliff book, "Thermal Shutters and Shades" gives a value of R2.7 for a single sheet of aluminized mylar.

But, an R4 shade will cut the heat loss from a high quality window by more than 50% -- pretty good for $15!

Gary

2/10/06

You can reach Doug at: dougkalmer AT gmail DOT com (replace AT with @, and DOT with a period)

Doug's Other Projects

Doug has contributed a number of projects to Build-It-Solar covering a wide range of solar and renewable energy areas -- see them all...

Thanks very much to Doug for providing this material!