Radiant barrier shades

I used radiantguard aluminized tyvek to make heat reflecting shades for a large bank of western-facing windows in my house. I couldn't be more pleased with the results. Right now (3:30 PM EDT), the outside of the shade (between shade and window) measures 88 degrees F, the inside measure 78 degrees F. More importantly, I can no longer feel the radiant heat coming in through the windows. For example, the floor in front of the windows is no longer warm.

If you're looking for some cheap fixes for old windows, this is one. It almost entirely prevents the transmission of infrared radiation through the windows into the inside of the house. Basically, it works as low-emissivity glass would. And it should work to prevent the emission of infrared from house to outside in winter.

Couldn't be easier to make. Buy the cheapest roller shades you can, take the original shade material off the roll, cut the radiant barrier material the same size, tape it to the roll, then roll up the shade and install it.

This material is not shiny like aluminized mylar -- it's more of a matte aluminum finish. With a set of sheer curtains in front of the shades, you wouldn't know these were anything other than regular light-blocking shades.

As long as at least one face of the material is exposed to an air gap, it should work. So, adding insulated drapes over the shades should not affect their ability to block infrared flow into or out of the house.

 

I bought mine from here.

Radiant Barrier Products - ARMA FOIL - Energy Efficient Solutions

They package the stuff for people who are going to line their attics with it, so the smallest 48" wide roll they sell is 125 feet long and about $70 plus shipping. Far as I could tell, that pretty much seems to be the standard size and price for this stuff (google radiant barrier foil and see what shows up). Some vendors offer smaller widths. The size didn't bother me as I have uses for at least that much, but I can see where that would be overkill for just a few shades. But you can always line your attic with the leftovers.

Home Depot sells its own version, but the description for the Home Depot product says the core is kraft (paper), which I figured would not work as well as a fabric core. But it might, I don't know. The Home Depot roll is $62.

Solar Shield 4 ft. x 125 ft. Foil Radiant Barrier - 4125 at The Home Depot

The fabric-core material definitely works, though. It's just the right thickness for this. The material handles like a fairly stiff fabric (which is what it is). The resulting roller shade will be a little bit fatter (when rolled up) then the stock shade as it comes off the shelf at Home Depot, but not so much that it exceeds the clearances between shade hardware and frame (for a 7' tall window).

This is not pretty material -- it's a dull silvery color, and you can see the coarse cloth underneath. But that works well. Yesterday we had a friend of my wife's walk right by the new shades (all 7'x2.5' x 3 of them, behind sheer curtains) and she didn't notice a thing. So, from the inside, at least, they don't scream "cheap insulation". From the outside, it definitely looks different, but again it doesn't jump out at you as (say) shiny mylar would. You have to have at least one side exposed to the air for the reflective/emissive properties of the foil to work.

You'd also need to pick up a roll of aluminum HVAC (duct) tape at Home Depot or similar for sealing up the pocket at the bottom of the shade where the wood or plastic bar sits. Also works well to tape the material to the shade roller.

So far I've made (fixed) skylight shades and roller window shades, and I've cut a piece to sit over the cargo area cover in the back of the Prius to keep the battery cooler in sunlight. I haven't tried laminating it to a fabric backer yet, but that'll be part of my next task, which is an insulating/reflective shade for a large bay window.

 

Pictures: The camera flash makes it look a lot shinier on the inside than it actually looks. The non-flash inside picture is closer to how it looks in real life.

 

Godiva, thanks, we've been looking for "two sided fusible interfacing" and coming up blank in the fabric stores around here. Now that I've got the brand name, I can buy some.

For this stuff, you don't have to treat the edges at all. Snap a chalk line on it, run the shears or skil knife down the line, and you're done. The material is completely fused together - no raveling.

We tried some Dritz stitch witchery (same concept as wonder under, but comes as a tape). That worked fine, though the radiant barrier did tend to crinkle in the heat. Just couldn't find broad pieces of it.