. As a baseline, the current cooking practice was considered, which is the use of three stone
fire as the only cooking system (fwood = 100%). Lower heating values were taken by Harker et al. (1982) as suggested in the protocol of WBT. The baseline thermal efficiency of three-stone fire, as the ratio between energy used and energy consumed, was assumed 15%, according to KPT performed on site by the authors (Vitali, 2012).