We tested three kinds of stoves to determine which one cooked food the fastest while using the least amount of of firewood.

The StoveTec was designed by Aprovecho Research Center in Oregon, USA and manufactured in China. It has a diameter of 26cm and a combustion chamber made from lightweight clay. StoveTec comes with a removable metal pot skirt that can be wrapped around a pot to force heat flow closer to the pot's sides and bottom. This increases heat transfer to the pot and could cut down on cooking time. The pot skirts were too small for the pots that people in Mbola used.

Envirofit was designed by Envirofit International in close cooperation with Oakridge National Research Laboratory in Tennessee, USA, and the Engines and Energy Conversion Laboratory at Colorado State University’s. It is also 26cm in diameter and was manufactured in India.

Advent was manufactured locally in Tabora, Tanzania by Advent Technologies. The diameter of the stove is 22 cm. The combustion chamber is made from a mixture of clay soil and sawdust. The height of the stove is 35 cm.