starwars wrote:I have been wondering if a water heating system might work. You have a campfire, so put a coil of tubing in the fire and pump water to a car heater core inside the teardrop.
I've thought about doing this myself (as a Licensed Heating and Cooling guy and an Engineer). I probably would if I weren't shooting for super-light weight to tow with my Ford Focus. (I'm hoping to keep my finished, hard sided popup for 2 under 500lb, 600 with gear). Warm floors in winter...excellent!
Keep a good fire going all day and you can heat all night if you bury the coil under the earth.