I'm building a small (160 square feet) granny flat about 20' away from our main house. Our main house has a great blend of pellet stove + solar collection to keep the home warm. Rather than run electricity or install a wood stove in the granny flat I was hoping I could run ducting from the main house.
I'm planning on a simple 12V solar system for the granny flat's electricity, hence nothing powerful enough to run a heater.
I've seen R8 flex ducting, but it seems weird to dig a trench for ducting even if I re-enforced it in a box. Is there any best practice for running ducting through an outdoor stretch? I'd rather have it be underground regarding aesthetics.
Temperature-wise we're around 8,000 feet in the mountains, temperatures dip down to -10°F in the winter, highs in the single digits (~5°F) on occasion. Normally winter days are 35°F highs and 5°F nights.
Is there any best practice for running ducting through an outdoor stretch?