I'm interested in using your little cod to help heat a small, very tightly built, cottage. Would it be possible to hook up an external air supply to the little cod to draw the combustion air from outside?
Yes certainly. We can supply a kit that will duct fresh air close to the stove. It's made up of a 4" flexible aluminum tube, an external wall jack (in copper or stainless), and then a "supply grate" that will be located near the stove. We've been speaking to people about these kits but so far none have shipped for any particular projects. People have elected to just keep a window cracked while the stove is in use. Happy to hook you up!
When we discussed this with our EPA certification lab, they said that its actually not the safest thing to do.
What can happen is that the piping roles can get reversed and the pipe meant to feed air can become the chimney! Not good when the supply pipe is not rated for chimney duty! One of the nice things about a stove is that it effects a change of air in a tight structure - getting rid of old air and the associated slow thinking that accompanies it.
a building official once told me he saw a video of flames shooting out of the house though the "vent" on a direct vent hook-up installation.
here is the rub. one can see why one would want a sealed loop for combustion. lots of other appliances are set up that way, often with a tube within a tube type combination vent and exhaust (sometimes/often with a fan assist). however, the exhaust on a wood/coal stove is much hotter (fans not practical), and therefore more dangerous should you experience negative pressure in the home. always your home (boat ) must have positive pressure for a natural draft appliance. if it is negative and less than the draft of your flue you are in trouble.