The other day I went to the NWTF branch office in Hinigaran to interview clients that recently purchased an Envirofit cookstove. Cookstoves have received a lot of positive publicity recently as a cheap and effective solution to the problem of indoor air pollution – a problem that claims 1.4 million lives every year. The predominant stove in use by the poor – a basic design with a fire lit beneath a pot resting on three stones (a “three-stone stove”) – burns inefficiently. Much of the heat from the stove is lost due to lack of insulation and the fuel – sticks or charcoal – does not burn completely, requiring more to produce the same amount of heat. What’s more, partially-burnt fuel produces smoke containing particulate matter that is particularly harmful to the lungs when inhaled. The Envirofit cookstove, designed in conjunction with researchers at the University of Colorado, is the product of air-flow modeling and rigorous testing. It is designed for efficiency.