Coincidentally yesterday, I was reading another blog, The Simple Dollar, and while I disagree a lot with the author (pretty much everyday, but it's an interesting blog irregardless), one of their readers sent in this way to cut air conditioning bills.
Today I tried it, and I'm so impressed I have to pass it on. You can find the original write-up here for more in-depth detail, but my personal adventure is below.
First - we have a total of four windows on the west side of our house. Almost all of our interior summer heat comes from these four windows. Today I went to wal*art (hate to give them any free publicity) and purchased the thinnest, least expensive tension curtain rods ($2.57 each) to fit our window width, four emergency solar blankets from the camping department (they're about the size of a pack of playing cards, but unfold to approximately 4'x6', and cost $2.98 each), plus a 99 cent pack of hinged plastic hair clips.
Total cost: $23.19.
Arriving home at 3 p.m. (peak afternoon sun heating time), I moved the first window curtain, raised the mini blinds and set the tension rod at the correct width. Then I unfolded the first solar blanket (pretty much just a large sheet of mylar as near as I can tell), folded it over the tension rod, securing it with two of the plastic hair clips. Then I snapped the rod into place over the window, lowered the mini blinds, and released the curtain.
Within 5 minutes, the temperature in the room had noticeably cooled off, and within 20 minutes, it was 20 minutes cooler. Placing my hand back in the window, behind the solar blanket next to the window pane, it was almost hot enough to burn my hand. All that heat had been coming in the window, and I was paying to cool it.The solar blanket is barely visible behind the shades.
Outside, it looks shiny, but, really, it's hotter than Hades out there, and no one is walking around looking at my windows. Or offering to pay my a/c bill so I can have more attractive windows.
We're about halfway through the next utility bill, and I'll let you know if there's a noticeable difference. We've already cut the a/c off today, because suddenly it's comfortable in here.