Any shop with a roll-up door can get really drafty. I came up with a fix for that problem, but inadvertently caused another.
By their nature, roll-up doors don’t seal very well around the edges. There’s usually a vinyl edging to help seal the door when closed, but the door rarely completes the seal all the way around. There are always gaps, some quite large, and during the winter it doesn’t take much for cold drafts to come howling through. And if you heat the shop, you lose a lot of it through those gaps.
I came up with an easy fix a few years ago that looks like this.
That’s just a cheap no-name toggle clamp mounted on an offset so it presses lightly on the door edge right at the guide wheel – where most of the leaking gaps are – pushing the door firmly into the vinyl edging. I put one at each of the guide wheels, six in all, and the difference is like night and day. All the heat I generate in the shop in the winter stays in the shop.
That’s fine 24/7 in the winter because you never want to lose heat, and in the summer if I’ve managed to get the shop relatively cool during the day, it keeps hot summer air out. But it didn’t occur to me that in the lengthy period from evening to morning radiational heat would raise the shop temperature overnight. The clamps were holding that heat in, even as it cooled off outside.
I don’t want a shop window or door open all night, of course, but it occurred to me out of the blue the other day that I could let the natural leakiness of the roll-up door work for me.
With the weather warming up I now keep those clamps closed during the day, maintaining the shop temperature as long as possible against the heat. Then just before I go to bed I’ve started opening those clamps. The cool night air naturally drafts in around the door edges – even more efficiently so if I pull down the attic access door to create an updraft – and by morning the shop is comfortable again.