How much air intake does my DIY hobo stove need?

> I'm curious if there are any general guidelines for the total area of air intake needed for a given volume of firebox.

WOW, that's a really good question. Hopefully the serious stovies will take it on. It does seem true, that stoves vary greatly in their need for air. There are breathers, and there are wheezers. I have one alcohol stove (a Packafeather) that varies air intake to vary heat output. The flame is more dependable when wide open. I suppose you could proceed "iteratively," try a minimum number of holes and see if you like the result, add more as needed.

Regards your first question; haven't tried, but I DID have that same idea for holes in a windscreen around a supercat stove. I put holes around 2/3 of the perimeter. FAIL. It gave me a severely lopsided flame, which simply avoided the side with no holes.

Please post back what you decide to do, sounds like an interesting build.

Derek, I believe there are general ratios for intake/firebox/vent. I base this on reading I did to build a wood burning oven. The best reference I found was actually a book on kiln (ceramic) designs. Very good book; I don't have it; if I took notes they are deeply buried. So that's a long way of saying, yes, but I don't know them.

In the last two weeks I built and tried another hobo stove, this design from the Skurka website, the 1qt paint can. Holes at bottom, wide slot to feed sticks & accomodate handle. Firing it in the wind, I had no problem with holes upwind and the slot downwind. In fact, desirable. With so much wind that the vent holes would be a problem, I'd put my everpresent MSR aluminum windscreen upwind.

You could drill the heck out of the lower sides (think of them as lightening holes) and wrap with a variable amount of aluminum foil to find the ideal open area.

The biggest issue I've seen with hobo stoves (I've made four or five) is not the air intake but the top venting for exhaust.

If there's enough top venting for exhaust, it will pull up enough air from the air intakes at the bottom, even if those intakes are smaller than normal (or if there are fewer of them than normal). If not, you wind up with a very smoky, inefficient burn.

Make sure that your pot does not choke off your top exhaust but is still in a place to gather the heat from that exhaust and you're pretty good to go.

Looking forward to what you come up with!

At a minimum, your airflow out the top of the stove should equal or exceed the air inflow. If you are using a pot that is much wider than the stove, increase the outflow even more.