Do you know what is so efficient about a little Rocket Stove?
A: Insulating the heat chamber reduces loss of energy in the burn
A: Options for insulation material: you can even use a sealed chamber of air as insulation as long as there is no movement of air in the chamber – movement of air looses energy. Easy insulation materials [that don’t burn] include perlite or hemp and lime or gritty wood ash (without any charcoal). If you want upcycled materials then you can use lightweight, non-flamable materials in approx 5mm size particles. Dense materials like sand simply absorb and transfer the heat to the outside, you don’t want any heat transfer. Insulation that is includes pockets of air between the particles is less conductive and a more effective insulation.
A: The most amazing fuel comes from oily trees that combust easily in Wild fires (Eucalyptus, Pine), the worst fuel is wet timber or papery wood such as palm fronds.
A: the gap ensures good air flow. If you angle the inlet tube it could look ugly BUT the sticks will fall in as they burn away. This is handy if you want a rocket stove heat exchanger for heating a green-house etc.
A: The pot inset would have more heat due to the thermal mass of the insulated chimney but a skirt is still better than a free standing pot.
A: A lid makes the pot boil quicker because we all know that a watched pot never boils. Perhaps water likes a little privacy.