"Space blinds"

I think these ideas may be useful to other people who are striving to reduce energy consumption in their houses.

I live in a condominium unit on the first floor, which is an end-unit with two sides. Around the houise are a nice lawn and three narrow patios. The house has six sliding patio doors in total, three of which are in the living room. These three sliding doors occupy most of the surface of a single large wall, which is about 23 feet wide by 8 feet high. My goal was to come up with a kind of window treatment for this huge “window” that was functional, pretty, and very effective in minimizing heat transfer in and out of the house.

After much investigation and thought, I decided on two tiers of window treatment. Tier 1 (closer to the glasses) would be a standard vertical blind set with each slat wrapped in a strip of space blanket. Tier 2 would be ceiling-to-floor opaque drapery (suede). So far I have completed Tier 1 but not yet Tier 2, though I have already bought the fabric. So the focus of this posting will be on Tier 1.

The core idea was to take advantage of space blankets as much as possible. Space blankets are an excellent insulator (radiant barrier) but in order for them to work most effectively there has to be about one inch of clear space in front of the shiny film. So I thought that by cutting out wide strips of space blankets and wrapping them around every louver of a vertical blind set I would ensure that that condition would be satisfied on both sides of the space blanket—and they would be very effective in blocking both the incoming radiation (in the summer) and the outgoing radiation (in the winter). The blinds and the film cooperate very nicely—the former provide physical support to the film and allow flexible use (opening/closing), whereas the film provides superior insulation. Moreover, this can be achieved at a very low cost—essentially the cost of the blinds, since space blankets can be bought for $1 and each of them is sufficient for as many as six louvers. This is well below 30 cents for each louver (including any other material that you will need).

That was the theory. As soon as I started the work I noticed that the blinds were looking very good. This was a big surprise to me as I had expected that all that shiny film would look ugly and I would really need the drapery in front of the blinds to hide them. But I was wrong! You can judge by yourselves. Opinions may vary, but many friends who have seen the results in person in my house have made very positive comments.

First of all, the film is so reflective that it acts as a double mirror—when you turn the blinds outwards, even a narrow space left between the slats will let some light into the room. And that “light” is actually an image reflected from outside, as opposed to, say, diffuse light. It’s not a perfect reflection, of course, but it’s sufficient to create an illusion of transparency. The eye is fooled into “seeing” the lawn and the trees “through” the slats, as if they were transparent (I can ensure you that they are absolutely opaque). One gets the impression of looking through a set of icicles hanging from the top of the window, regularly spaced. Turn the blinds a little bit more and the image disappears.

The other nice detail (also unexpected) is that the little folds in the space blankets (due to the packaging) create a very pleasant pattern on the surface of the blinds.

Overall it looks like a massive set of blinds made of ice, and it’s hard to believe it was not designed to look like that, or even to look pretty.

Here are some pictures.