Hi. I'm working in a collective to build a foundry + metal shop. We want our furnace to be as ecologically sound as possible, so we want to maximize combustion efficiency and heat conservation. Unfortunately, all the existing example metal-melting furnaces I have seen so far have little consideration for these priorities.

To get around this research blockade, I'm thinking that maybe resources regarding 'sustainable building' might have some relevant design strategies that we could apply to the furnace. Maybe some folks have found a way to modify/build their home fireplace? I'm not really sure where to start looking.

(We are not dead set on any fuel type--we'd prefer to have the ability to use a diversity of energy sources, so this should not limit the search.)