Sometimes things work out great, just as you envision. Other times, things don't go as you imagined. That's the case with our most recent project, a warming hut that we built for use during biochar retort burns. It's a lot better than not having it, but it needs a little rework.
When you're doing something that isn't standard, kind of outside the box, sometimes you have to make adjustments. We had that experience with our subtropical tree greenhouse roof. John Wells of Rimol Greenhouses told us nobody had ever done a lean-to greenhouse like we designed, with two roll-up roof curtains all the way to the top, but he helped us work it out. It would have worked great too, except for the falling icicles. Anyway, we had to replace the upper part of the roof with "hard" polycarbonate plastic, instead of "soft" polyethylene plastic. We think it came out looking great, but even better, this winter it has worked out exceptionally well. The greenhouse is tighter and has a reduced heat load. Last winter, icicles falling from the overhead eave of the building which abuts the greenhouse punctured the outer layer of polyethylene, allowing the trapped air between the two layers of poly to escape. This increased the heat load, and every time the wind blew hard (which is all the time here on the hill), it sounded like the greenhouse was going to be ripped apart by the flapping plastic. This winter the falling icicles hit the polycarbonate (which is loud) and then just slide down and off the greenhouse. No harm, no foul. And we'll still be able to open up the lower portion for the summer, after cold weather is past.
Our latest miscalculation, the design of the retort warming hut, has an easier fix in front of us. The hut has solid walls on three sides. The side facing the retort is open with overlapping clear vinyl strips hanging down, like you see in grocery store coolers. The intent was to allow clear visibility of the retort to monitor progress of the burn and easy egress for tending the controls, but also retain heat. It would have worked well except for that ever-present wind we have, which keeps blowing the vinyl strips open, cooling off the hut. After a month's use in cold, windy weather, Ron just installed a temporary half-wall, but we plan to put in a more permanent fix this summer. Even with the design flaw, the hut has been a godsend for the retort operators (so far, usually Rich and Ron, occasionally me) during this unusually cold winter. Fortunately, I was able to build it inside our shop, where it's warm. When it was finished, Carol and I pushed it out though the garage door (just barely making it through), rolling it on steel rods. Then we hooked it up with a chain to the tractor, and Ron just pulled and pushed it on the snowpack into position. After we leveled it with a few blocks, it was good to go. We're undecided if we'll pull it away for the summer season, or leave it in place for shade. It's portable, so we have options. Steve