Traditional cookstoves are typically both fuel-inefficient and polluting. Emissions from such
stoves have a profound impact on indoor air quality in homes around the world, causing
major health problems. In response to Uganda’s growing energy, health and environmental
issues, efforts have included a focus on disseminating improved cookstoves. Some improved
cookstoves reduce fuel use but studies have not yet considered their potential to reduce
emissions. This research was aimed at quantifying the emissions from the 3-Stone fire and
improved woodstoves and to compute the likely reduction in carbon monoxide (CO) and
Particulate Matter (PM) emissions that these improved stoves could provide. It was
hypothesized that the greater fuel efficiency of improved stoves would reduce the mass
emissions compared to cooking with a 3-Stone stone fire. The 3-Stone fire and four improved
wood stoves (Upesi, Envirofit, Mwoto and Save 80) were considered for this study because
they were on promotion in Uganda. These stoves were tested following the standard Water
Boiling Test (WBT) version 4.2.2 for emissions and efficiency testing in a controlled
laboratory. Five tests were conducted for each stove during which both CO and PM
emissions were recorded at 1-second interval using the Portable Emissions Measurement
System (PEMS). On average, the CO emissions for the 3-Stone fire, Upesi, Envirofit,
Save80 and Mwoto stoves were 66g, 48g, 33g, 32g and 29g respectively, whereas the PM
emissions for the 3-Stone fire, Upesi, Envirofit, Save80 and Mwoto stoves were 443mg,
331mg, 220mg, 224mg and 162mg respectively. The CO emissions reduction for Upesi,
Envirofit, Save80 and Mwoto were 28%, 49%, 51% and 56% respectively, whereas the PM
emissions reduction for Upesi, Envirofit, Save80 and Mwoto were 30%, 49%, 50% and 63%
respectively. The differences in emissions between 3-Stone fire and all improved woodstoves
were significant thus; improved woodstoves, if adopted, have a capacity to reduce CO
emissions by 28% to 56% and PM emissions by 30% to 63% depending on the type of stove.
This implies that improved woodstoves can potentially benefit users in terms of fuel
efficiency and reduced emissions which eventually would reduce adverse health effects.