Wow, excellent write up, good job! Yes it was long, but it was all interesting information and I read the whole thing
. That is an interesting setup, so you are actually burning the fire inside the water to heat the water? I guess just another way to build a boiler. I do like the idea of having the fire outside of the house and use water to transfer the heat. I did similar, but converted a home heating oil boiler and have it in the garage with with water pipes going into the house. Heat is transferred using a plenum insert (basically a big radiator) and built a box similar to yours and used a squirrel cage fan from an old furnace to blow heat into the propane furnace ducts. Thanks for taking the time to share and post pictures. Awesome project. And love the efficiency OCD too. I get it, why burn to heat up the outside air... not really the point. Get those BTU's inside, or Kw's as you refer to them
. And I fully agree, the black diesel oil is the worse... black stuff will stain things up in a hurry. I am always pleased when I get friends gasoline engine oil. Its still sometimes brown and has a slight sweet smell of gas.
Thanks again and safe burning!