Help with a new build Please

Hi all, am planing on building a rocket stove heater (without the mass) I intend to build the fire box and riser out of fire bricks. A couple of questions have arisen . (1) Do I have to insulate the outside of the burn chamber and the riser?Would be nice if I didn't have to.(2) is there a minimum clearance measurement for the gap between the outside of the heat riser and the inside of the outer barrel.Cheers Pete

Yes, you need to insulate the burn tunnel and riser. If you don't you will lose too much heat from the combustion zone and won't get the super-efficient clean burn.


The minimum recommended clearance from riser to barrel sides is about 2". You could offset the barrel a bit and have one side only 1", but that would definitely unbalance the heat radiation from the sides. In certain situations that might be desirable. It might be okay to have the corners of the insulation-wrapped riser be a bit less than 2", as long as there is plenty of airflow space at the bottom of the barrel for all sides to reach the exhaust.

I presume you know that without mass, the heat will disappear soon after the stove is out; but you can't turn down the burn to a trickle to keep your space moderately warm, as it will not work efficiently that way. You would get creosote in the duct or chimney, which would burn the next time you had a long hot fire.

Thanks for your answer Glenn, Looks like I will have a little rethink me thinks.Heat soke will come later. Cheers

With some information about your situation, the space, intended use patterns, and climate, we could advise on the best options for you.