Research
Investigating the Applicability of Adaptive Comfort Model in a Naturally Ventilated Student Housing in Nigeria
Thermal comfort, influenced by thermal sensation is an important building performance indicator. In the context of this work, the applicability of adaptive comfort model (ACM) to simulate the thermal comfort level in a naturally ventilated hostel building at Obafemi Awolowo University, Ile-Ife, Nigeria was investigated. The applicability of ACM was investigated by determined the neutral and comfort temperature in addition to comfort range temperature of the occupants using the environmental data derived from field measurements and information from questionnaire survey. A total of 288 responses participated in the three months short-term thermal comfort field study. The results obtained were compared with the recommendations of ASHRAE Standard 55, ISO 7730 Standard and results of previous field studies located in the warm-humid tropics. The predicted neutral temperature was found to be 26.8 o C. The acceptable ranges of comfort temperature around thermal neutrality were 24.3-29.3 o C and 23.3-30.3 o C for 90% and 80% acceptability. These values closely matched the recommended range of ASHRAE Standard 55 and ISO 7730 standard. The results of this study indicated that the use of ACM seems to be promising regarding the prediction of indoor climatic conditions under steady-state non-uniform environments. The study concluded that the adaptive algorithms are more reliable to evaluate the thermal comfort in naturally ventilated buildings.
Thermal Comfort and Occupant Behaviour in a Naturally Ventilated Hostel in Warm-Humid Climate of Ile-Ife, Nigeria: Field Study Report during Hot Season
Naturally ventilated buildings have been observed to be ineffective in warm-humid tropical especially during hot season. To ascertaining this observation, this study presents the results of a short-term thermal comfort survey performed in a naturally ventilated hostel building in Obafemi Awolowo University, Ile-Ife, Nigeria during hot season. Using the data obtained from questionnaire survey and physical measurement of (air temperature, relative humidity and air velocity) using Kestrel model 4500, thermal environmental conditions, occupant comfort and adaptation methods were investigated considering class II protocol. Ninety six respondents participated in the study. Statistical analysis of students` responses and measured thermal environmental variables was performed to determine existing indoor environmental conditions and priority of using adaptive controls. All the measured environmental variables fell below the comfort range recommended by ASHRAE standard 55 and ISO 7730 standard. On the contrary, respondents were comfortable, preferring cooler, no change environments and more air movement. First preference of the respondents adaptive control was window opening (77.4%), closely followed by wearing light clothes (77.3%) and lastly, the use of electric fans. This study concludes that in warm-humid climate of Ile-Ife, during the hot season the desire for sustainable thermal comfort may not be achieved without mechanical ventilation system.
