Our house was built in 1866 and still has the original windows. The wooden sashes are in beautiful shape, and many of the wavy, handblown glass panes are still intact. Unfortunately, the windows are not airtight anymore (if they ever were), which means the house is not warm, which is why my wife turns up the heat, and then I turn it down, and then she puts on her parka.
I’ve spent a lot of time and a good bit of money searching for ways to make our windows more energy-efficient. I tried the plastic-wrap things you adhere with a hair dryer. I bought some metal tracks that were supposed to make the sashes fit more snugly in their frames, but they arrived dented, were flimsy, and I badly gouged one sash trying to install them.
The best product I’ve found is a newish one called the Indow Window insert ($250). It’s an acrylic sheet, laser-measured to fit each window, ribbed with compression tubing that squeezes into the window frame, sealing cold air out and keeping warm air in. Once you pop them in (no hardware required), you don’t even notice them. It’s the kind of ridiculously simple invention that you think must have been invented before.
I used them only this past winter, so I don’t have multiple seasons of research to compare, but the U.S. Department of Energy found that Indows led to a 20 percent reduction in energy costs in a sample home, and a separate, larger study found a 19 percent reduction. I used an Etekcity infrared thermometer to test the surface temperature of windows in my house with Indows and without, both in the same room and in separate rooms. The results are below.
My advice: Don’t wait until the temperatures start to drop to do something about drafty windows. It takes a while for your custom inserts to be made. First Indow mails you a laser-measuring tool. You take your measurements, enter them on the company’s website, mail the tool back, and then they make your inserts. It’s all fairly simple, and they’ve worked out all the bugs, but there can be slowdowns during the high season. Order a set now, while no one else is. I’ve already ordered mine, so that next winter, no one in my home will feel the need to dress like a dog sledder while watching television.
By the way, when they arrive this summer and you’re trying to keep the hot air outside, I found this too: These things also work in reverse.
*This article origionally appeared in the May 2016 issue of Popular Mechanics.