Well, we will see what happens. The one thing left out of your excellent calculation is that it only runs 24/7 wow coming up to temperature. After that, it doesn’t fire very often.
I have a friend locally that does heavy truck repair. His shop is 50 x 100. He says when he starts up the heat in October, it takes at least a week to get the slab up to temperature. But once it is, the system only fires about once every seven or eight hours to make a circulation. His shop is bigger than mine, but they work in short sleeve shirts, all winter.
Another friend up the road for me also has a 50 x 100 barndominium, with approximately the back third being a two-story apartment. Last year was his first winter in there. He went with spray foam, and he has a natural gas heater. His highest bill last winter was under $120 per month. And that included heat and electricity. So that made me hopeful as well.
In the end, I didn’t have anybody to teach me any of this. I studied as much as I could, thought about it as much as I could, asked people I knew that had similar as much as I could, then made a decision. The whole point of radiant heating is that it’s expensive to install but extremely cheap and efficient to operate. That’s why I went for it. If it actually comes out to two grand, or one grand, per month to keep it 40° in the shop, I’ll have to get a new plan. Not the end of the world, just part of the process.
