(The first problem with windows, as we learned in a recent post, is that they allow architects and others to work indoors, where they forget about things that could interact negatively with their constructions, such as the Sun.)
But this cold day reminds me that windows often get a bad rap for the wrong reason.
Many people think an old, single pane window is a gaping wound in a home’s “envelope,” bleeding heat into the frosty world. And they’re right: The basic window glass has a R-value of 1. One. Uno. Next to null.
So swap that antique out for a vinyl double-hung unit!
Except: The is the R-value of a vinyl replacement window is perhaps R-3.
Yay, you tripled your insulating power across those 18 square feet.
Boo, the current standard for roofs is usually R-38. So you’ve just spent a boatload of money for a nearly-inconsequential improvement in a tiny percentage of your home’s envelope.
When I had an energy auditor go through my windy bungalow, he showed very little interest in my windows. He groaned over the vent pipe for my gas fireplace. He crawled into the upstairs crawl spaces, where I could hear him growl with disgust. It was gusty in there, where the roof met the walls in only a casual fashion. He backed out, shut the cute little door, and held a lighter up to the door frame. He scowled at me as the gusts flattened his flame.
Infiltration ranks above insulation, in the efficiency world. Insulation is great, if it’s in a sealed cavity. But air that can slip around insulation just hauls its frosty molecules straight into the house. “Filterglass,” the auditor called my insulation. It wasn’t stopping the cold air, it was just straining out some of the dirt.
So back to windows. Each edge, where wood meets wood offers an opportunity for leakage. As wood frames age, they shrink, no longer fitting snugly into their sashes. Wind finds these failures, and exploits them.
If you would like to feel really, really good about your windows, without buying replacement ones, assemble two items: a roll of cling wrap; and a small, metal putty knife.
Wait for a windy day, and address your first window. (Cold storms typically come from the west and north, so you might concentrate your powers there.)
Moisten the back of your hand, in the interest of not burning things up with a lighter. Slowly move your damp skin around the wooden edges of the window. You’ll know it when you find a leak.
Pull out two inches of cling wrap and tear it off. Collapse this two inches to a loose “string” of wrap. Place one end where the leak begins, and use the putty knife to work it into the narrow gap between the two pieces of wood. It will disappear. So will the wind. You will feel powerful like Zeus. Adding two layers of “window treatment,” such as venetian blinds and a curtain, will amount to a replacement window.
Repeat as needed, around the frame and where the upper and lower sashes meet.
There are a few things cling wrap can’t cure. On my north-facing windows, too much water and not enough sunlight had frankly rotted the wood. Panes of quaint old glass dangled in thin air, held to rotting wood by an antigravitational force yet to be named.
Those, the auditor said, I could replace. But only those. And then I could crawl into my crawl spaces and spend every cent I might scrounge up to unite my roof and walls.
Art note: That little bonsai tree in its massive prison is a little disturbing.