Neutral temperature determination study conducted in naturally ventilated residential buildings of Jimma town, south-west Ethiopia. 98 residential buildings were systematically selected and the questionnaire was administrated to adult residents in each of selected buildings. They were asked about their thermal sensation for consecutive seven days at living rooms in the morning, afternoon, evening and night times and their responses were quantified using a seven-point thermal sensation scale. Measurement and estimation of thermal variables were made in four of the selected residential buildings simultaneous to the survey study in the days of the dry and wet season of 2018/2019. From the linear regression analysis, thermal sensation vote had a strong linear relationship with air temperature. The ANOVA of the analysis gives the relationship by the equations TSV = 0.331 Ta – 8.456 for dry season days and TSV = 0.362Ta – 8.175 for wet season days. The neutral temperatures in the residential buildings of dry and wet season days were 25.50C and 22.60C respectively. Residential building occupants utilize natural means to make their indoor environment thermally comfortable for varied neutral temperature of the seasons. Natural means make the indoor environment thermally comfortable and affordable by all citizens, consumes no energy, and eco-friendly.

Keywords: Air temperature, Neutral temperature, Relative humidity, Residential buildings, Thermal sensation votes