I helped a guy I used to work for (also a good friend) build and operate a waste oil heater that also burned wood, to heat our shop. Waste oil is easy to come by, you just need storage and a way to transfer from containers. Mixed gas can be a concern. Our setup would get hot enough to melt the stove. I'll see if I can find a pic. A more efficient version of what we had would be "cool"... far away from the house.
I also assembled a manufactured waste oil heater for another employer. It was a complicated mess to put together. Needed fine tuning sometimes but was awesome when it was running right. I'll try to remember who made it.
I'd guess the manufactured heater was less efficient (more costly) than what we made due to the electrical cost. The one we made from scrap was gravity fed and no electricity other than a blower.
Bookmarks