This picture is worth a thousand words. Just do this, and you won’t have to read the rest of the post. But by all means if you prefer reading about stuff you should do, rather than actually doing it, read on. We’ve all been there.
I, for example, read up on replacement windows every November-December when the first blast of Arctic air barrels into my 1918 bungalow. “Next summer,” I vow.
Then, each “next summer” I do not replace my windows, for a number of reasons. Not least, the bungalow is a tropical vernacular, and tends toward enormous windows on the first floor. Your average vinyl replacement unit would soon warp under the weight of all that glass.
But another reason is that replacing windows just doesn’t save much energy. Even brand-new, double-glazed windows are relatively worthless when viewed as insulation. Two layers of window dressing (roller shade + curtain; Venetian blind + Roman shade) give you the same insulation value as a double glazed window. But only
only if air is not leaking around the edges of the old window unit.
Aaaaaand even if air is leaking around the shrunken frames, rattling them like frosty bones and causing your candle flames to dance merrily, you still don’t have to replace them. Just do this:
1: Tear off strips of cling-wrap.
2: With a fillet knife, putty knife, whatever, work that cling wrap into the crack between the window sash and the window frame.
3: You’re done. Go read something enjoyable.*
No hair dryer. No gray, gummy ropes of… gummystuff. The cling wrap disappears into the chasm, not to be seen again until spring.
*Extra credit for stuffing cling wrap into the pully mechanism at the top of the window.