Evidence for reduced performance discrepancy of improved cookstoves at laboratory and field

The discrepancy in the performance of improved cookstoves (ICSs) in laboratory and field settings has been well demonstrated, with field results portraying considerable decrease in performance resulting in partial fulfilment of claims due to various factors. This study aims at determining possible discrepancy causing factors-categorised as controllable and uncontrollable. Additionally, performance discrepancy of various cookstoves was explored by testing them in both the settings, keeping the controllable factors consistent. The testing method was in line with Bureau of Indian Standards protocol for testing one traditional cookstove (TCS), three natural draft ICS and one forced-draft (FD) ICS; the cookstoves were evaluated for total particulate matter (TPM), carbon monoxide (CO) concentration measured in the proximity of the cookstove and thermal efficiency. Results reveal TCS to be the major TPM and CO emitter in both the settings, while FD stove was the cleanest. Average increase of TPM and CO in field was found 31% and 33%, respectively, with 10% decrease in thermal efficiency compared to laboratory. Statistical analysis shows substantially less laboratory and field performance variations as compared to previous studies. However, deviations in the results were attributed to uncontrollable factors like kitchen aspect ratio, air exchange rate and local weather among others which are dissimilar to laboratory conditions. Findings from the study are helpful in synchronising the laboratory and field performance by strictly adhering to the controllable factors and outlining the uncontrollable factors while testing before certifying stoves.