Field Studies of Thermal Comfort in a Naturally Ventilated Large Space Building in Maiduguri, Borno State
In a hot climate like Maiduguri, one of the conventional approaches for providing comfortable environment is the use of natural ventilation. In some cases, this strategy does provide the suitable thermal environment in a large space building such as the mosque. This study evaluated the thermal comfort of a naturally ventilated large space building, the university of Maiduguri central mosque in Maiduguri, Borno state during different times of daily prayers. The field study was conducted in 16th December 2015 (harmattan season) and April 2016 (hot season) during subuh, zuhr, Asri, Magrib and Ishai prayer times. During these days, the objective measurement using LUTRON ABH 4224 Cup Anemometer instrument and subjective assessment using questionnaire were accomplished. The objective parameters measured were air temperature, relative humidity and air velocity and the subjective responses concern the thermal condition of the respondents. Through linear regression analysis, Predictive Mean Vote (PMV) model was developed. The results obtained showed that majority of the worshippers found the thermal condition unacceptable in the naturally ventilated mosque even though the thermal sensation exceed the one specified by ASHRAE standard 55. Also, from the PMV model developed, the comfort range of temperature was found to be between 29.6 to 32.8 o C and the neutral temperature was found to be 31.2 o C.