Q–I have an old house with 36-inch double-sash windows that let cold air in during the winter. I remember seeing a “This Old House” segment where a contractor removed the sashes, fixed them up, and then replaced the cords and pulleys with a vinyl insert. They also filled the old cord cavity with insulation.
Do you know of anything like this in our area? I do not want to replace the windows, but I’d sure like them to be more energy efficient.
Marty Whalen Jr., Kankakee
A–You’ve hit on something good. What’s known as “channel kits” are an excellent update for old windows. What’s more, they’re far cheaper than a replacement window, notes John Marley, an administrator with the Energy Wise Homes program run by the Illinois Department of Commerce and Community Affairs.
“The kits do a great job,” he says. “You can really notice the difference.”
After the channel kits have been installed, your heating bills will reflect the upgrade as you dial down the thermostat. In addition, you can continue to enjoy the aesthetics of your existing windows.
Channel kits, also called “replacement channels,” are somewhat difficult to find. You might want to start by calling around to lumber yards or more specialized home improvement stores.
These kits provide weatherstripping to older double-hung windows, which are notorious for letting cold air leak into the house. They replace the old rope-or-chain, pulley and weight mechanism with a more modern system that’s found on newer windows.
The kits also silence loose windows that rattle in the wind.
On the down side, installation takes some time and lots of patience. If you’re not an able do-it-yourselfer, try to find handyman to do the job, which can get a bit messy.
The kits, selling for about $20, provide two aluminum or vinyl channels with tensions springs in the center to replace a window’s rope or chain system.
A problem with the channel kits is that they’re designed to work with windows of a certain depth. Windows that are any thicker or thinner need to be shaved with a router or built out with furring strips to fit the channels. Check the requirements on the kit’s package.
Before you buy a kit, make precise measurements. First measure the depth of the sash, then open the window and measure the bottom of the lower sash. The top of the sash, also known as the locking rail, is wider than the bottom. Also measure the length of the window, from the top of the upper sash to the bottom of the lower sash.
To install the sash, you’ll need to disassemble the window. First remove the sashes, then open up the cavities that contain the weights and chains or ropes and remove them. Also remove the pulleys at the top of the window.
For detailed information, check out a home improvement book that covers fixing broken sash cords or chains. It’s practically the same job.
Before installing the new channels, fill the side cavities with insulation, which will greatly reduce cold air infiltration.
Marley recommends using cellulose insulation fill over pieces of a fiberglass blanket. “It will do a better job but needs to be blown in, which can get dusty,” he says.
Alternatively, you can cut strips of rigid insulation board and layer several to fill the cavity. Then cover the perimeter of the top strip with a bead of caulk. This method, however, will require that you expose most of the cavity.
After installing the insulation, attach the new channels to the sashes and apply horizontal weatherstrips to the bottom of the lower sash, the top of the upper sash, and where the two sashes meet in the middle. Finally, put the sashes back in the window opening.
It’s also wise to caulk the perimeter of the window from the outside, to better seal out drafts, says Marley. And be sure the windows are properly glazed.
Overall, it’s a fairly elaborate job but it’s a lot cheaper than a replacement window, which can run hundreds if not thousands of dollars. “And you’ll notice a significant difference right away on a cold day,” says Marley.
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Got a question about home energy or home environmental issues? Write to Energy Q&A, Chicago Tribune, Your Place section, 435 N. Michigan Ave., 4th Floor, Chicago, Ill. 60611. Or you can e-mail energy qa@aol.com. Questions will be answered only through the column.
