So I've got this nice little shack in the backyard that I use as my office. Mostly I write in here, but I also work the day job here, plus I've got my workbench out here for dorking around. It's small, only 10'x12', but it's enough for what I do.
Now, I have electric run out here, one 20-amp circuit, which is plenty for my laptop and monitors and LED lighting. As it turns out, it's also enough to run an electric space heater, which is how I kept the place warm last winter. But the electric bills got out of hand, and I decided to go "off-grid" with my heating this year.
Natural gas would be my fuel of choice, but trenching from the house to the shack for a buried gas line would have been prohibitive. So propane it was to be. I found a wall-mount direct vent propane heater rated at 8000 BTU/hr, which seems about right for this size space. Trouble is: how fast will I go through a tank? And what happens if a tank runs dry in the middle of the night?
My immediate goal here is to build scales to sit each of the two 40-pound propane tanks on, and connect those scales to some kind of IoT system. I want to be able to graph change in weight over time, so I get an idea of the rate of fuel consumption. I also want a heads up on when a tank will be going dry, in the form of an email or text. I may also include an outdoor temperature monitor so I can correlate degree days with fuel usage.
Stretch goals include adding remote control to the heater so I can warm the shack up in the morning without getting out of bed. That might prove challenging since I'd have to link the heater's mechanical controls to a servo. We'll see where that goes.