Maybe this is crazy, but I hate the idea of an electric heated waterer in the winter. So, what if you built a rocket mass heater around the water trough and burned it once a day to keep the water from freezing. Probly need to insulate the mass not in contact with trough to retain heat longer. Any ideas or obvious issues?
just don't let the water get in contact with the firebox itself. Might need a little shed roof to keep weather out of the stove, and store some dry firewood nearby.
The water itself will have way more thermal mass than your cob (about 3 to 4 times as much by volume) so you shouldn't need much masonry if you can insulate and weatherize it.
seems like a sound idea in principle.
You could even stage a pot of hot water on top of the barrel, with a tap on the side to drain it into the tank and heat things up that much faster. You shouldn't need more than a 30 to 45 minute fire if you are dumping hot water in directly to mix with the cold in the tank.
If you want to insulate the barrel, don't - but you can heat shield it with air gaps, and force more of that heat up around the pot.
It does seem like a chore to trek out there and fire up the heater, tho, which is probably why people go to electric. You can just leave them on, sucking little dregs of power off the grid, and you keep your toes warm indoors.
If this is right near your house / barn and you go there daily anyway, I'd be tempted to rig things so you get a little more heat into the building from it and just use the hot water from atop the barrel to heat the stock tank. Make a warm spot the stock hang out in, and they may also serve as thermal mass / buffers to reduce the heat loss and keep their water thawed.
Yup, the pocket rocket or snorkel heater is the way to go. I used a 55 gallon pocket rocket in an 8 foot tank (700-750 gallon). Biggest issue is ballast to sink it. I used a cast iron flywheel I had in scrap plus sand. Next time I will put a 30 gallon inside a 55 and put sand in-between--that will get the fire lower into the water and act as a buffer so the heat isn't sucked out of the fire too fast (it would creosote the side of the barrel at times).
You can buy one from cowboyhottubs if you don't have the skills to make one, but it isn't a rocket.
"You must be the change you want to see in the world." "First they ignore you, then they laugh at you, then they fight you, then you win." --Mahatma Gandhi
"Preach the Gospel always, and if necessary, use words." --Francis of Assisi.
"Family farms work when the whole family works the farm." -- Adam Klaus