Do thermal curtains work? Yes. Do thermal curtains keep cold out? Yes. Do thermal curtains block light? Yes. If you’re interested in them, here’s where to find them.

My wife and I went shopping for thermal (also known as blackout) curtains. I’d read about them in comments on financial blogs but never saw much else in the way of first-person testimony about them.

Where to buy thermal curtains

First of all, they aren’t hard to find as long as you know what to look for. Kmart and JC Penney sell the Eclipse brand of thermal curtain. They aren’t terribly expensive either. The cheapest Eclipse curtains at Kmart start at $16 per panel. They’re even cheaper at Amazon. JC Penney has some that sell for $55 per panel. I’m sure I could find some that are costlier still, but remember, I’m Scottish so I didn’t look. So whatever price range you’re in, you can find something. Just go wherever you’d normally buy curtains and look for the words “thermal,” “blackout,” and/or “energy saving.”

How thermal curtains work

The curtains don’t look terribly weird or anything. They have a white lining. In the winter it keeps cold out like a quilt. In the summer it keeps heat out by reflecting it. If you were expecting foam reflective panels like what people put in their car windshields, you can stop worrying.

The principle is sound. When my A/C went out in the dead of July, I combated it by putting white foam board everywhere the sun was coming in. The house stayed noticeably cooler–a couple of degrees at least. I wanted to try it with the A/C running, but my neighbors talk about me enough as it is. White-lined curtains in the window are more socially acceptable than white polystyrene foam.

Do thermal curtains work?

As far as I can tell, outfitting my house with thermal curtains saved me about $200-$300 per year. So the curtains pay for themselves in less than a year.

The package my curtains came in claims a potential 25% savings on your utility bill. If you have awful aluminum windows like me that need replacement desperately, that seems to be true. A window costs anywhere from $200 to $800 to replace. A set of curtains costs $32 to $200.

The curtains block most night noise and light from the outside, which can be nice. I can see and hear the local commercial district out my back window at night, which can be comforting, but can be annoying when trying to sleep. The curtains are a quality of life improvement in that regard.

The curtains don’t completely block direct sunlight but they really cut down on what gets in. We get some intense sun early in the morning in the living room and late in the afternoon in the kitchen and family room. With thermal curtains in the living room, the A/C didn’t kick in until 10 am. When I first got up, it was a comfortable 73 degrees in the house. We noticed the difference right away.

So if you’re renting, or just can’t afford new windows, I recommend these. They’re a cheap way to pick up some R value around the windows, where it really counts.

More energy saving ideas

I’ve done a number of other things to help me save energy over the years. Most are pretty inexpensive. I installed thermal blinds. Then I insulated my hot water pipes. I insulated my electrical outlets and added child safety plates. Perhaps most importantly, I bought LED bulbs.

My electric usage dropped 19 percent in 2011, so these things work. Every bit helps. I don’t expect energy to get any cheaper.