Evaluating the Effectiveness of Bioclimatic Design Strategies in Warm-Humid Institutional Buildings (Published)
Warm-humid climatic zones present enduring challenges to achieving indoor thermal comfort in naturally ventilated institutional buildings. Despite growing global interest in bioclimatic architecture, empirical assessments of passive design effectiveness in public university buildings across tropical Sub-Saharan Africa remain sparse. This study evaluates the effectiveness of five core bioclimatic design strategies (building orientation and layout, shading devices, opening and ventilation systems, landscaping, and internal courtyards) in 62 public university buildings constructed between 2012 and 2023 across six state capitals in Southwest Nigeria. A mixed-methods approach integrated objective bioclimatic audits, Evans Comfort Scale and Mahoney Table analyses, indoor environmental measurements using a calibrated Kestrel 4500 Weather Meter, and subjective post-occupancy evaluations from 374 validated respondents. Findings reveal significant deficiencies in the implementation of all five strategy categories. Opening and ventilation systems registered the highest importance index (II = 4.17) among occupants, followed by landscaping (II = 3.67), courtyards (II = 3.34), orientation/layout (II = 3.21), and shading devices (II = 3.20). Multivariable ordinal logistic regression identified perceived indoor temperature (β = 1.58; OR = 4.86; p < .001) and air velocity (β = 0.94; OR = 2.56; p = .002) as the strongest physiological predictors of thermal comfort satisfaction. Building openings exerted the greatest design-based influence on comfort outcomes (β = 1.42; OR = 4.14; p < .001). Approximately 69.8% of respondents reported thermal discomfort, with afternoon conditions (12:00–18:00 h) rated most uncomfortable by 59.4% of occupants. The study establishes location-specific thermal comfort indices and bioclimatic design benchmarks for six Nigerian cities, contributing empirical data toward the revision of the Nigeria Building Energy Efficiency Code (N-BEEC) and advocating for the integration of adaptive passive design guidelines in institutional building policy.
Keywords: Natural Ventilation, Nigeria, Post Occupancy Evaluation, Thermal Comfort, bioclimatic design, courtyard design, institutional buildings, passive cooling, shading devices, warm-humid climate
Investigating Indoor Ventilation in Multi-habited houses: A case of Ogbomoso, Nigeria (Published)
The study investigated the indoor natural ventilation condition in multi-habited houses in the traditional core of Ogbomoso. Factors affecting natural ventilation in buildings such as orientation, external spacing, landscape and opening conditions were assessed through physical observations and direct measurements. Data on indoor air movement (velocity) was obtained with the use of kestrel 4500 pocket weather and environmental metre after due calibration with the climatic data of Ogbomoso which had earlier been obtained from the Nigeria meteorological station; the data was obtained in order to assess the level of ventilation and air movement in their various spaces. A living room, a bedroom and a kitchen (which are spaces where residents spend most time) were randomly selected in each multi-habited building for the purpose of the study. Obtained results were compared with the standard values given by scholars Borda-Dias and Chand. The study found all factors affecting natural ventilation to be grossly inadequate when compared with standards just as low air velocity level was also recorded in all their spaces (0.08 minimum and 0.48m/s maximum observed as against minimum of 0.50m/s recommended by Borda-Dias). The study concluded that there is a likelihood of high dependency on active driven mechanical devices in the study area if suitable indoor thermal comfort is to be achieved. The study recommended that a more awareness level on natural ventilation systems should be created and a rehabilitation of multi-habited homes in the study area is suggested.
Citation: Abdulrasaq Kunle Ayinla and Ilelabayo Ismail Adebisi (2021) Investigating Indoor Ventilation in Multi-habited houses: A case of Ogbomoso, Nigeria, International Journal of Civil Engineering, Construction and Estate Management, Vol.9, No.3, pp.1-15
Keywords: Energy, Natural Ventilation, Thermal Comfort, multi-habitation, natural cooling
Natural Ventilation and Body Heat Comfort: An Evaluation of Residents Satisfaction in Ogbomoso, Nigeria. (Published)
This study evaluates the variations in the level of natural ventilation in houses across the three main residential density zones of Ogbomoso. The study employs two approaches. First, it surveys the perception of residents with respect to the body heat comfort in their houses. Second, it examines the window opening sizes for compliance with floor areas considered desirable for effective natural ventilation in a warm humid climate like Nigeria. The main objective is to validate residents perception of body heat comfort through the assessment of window opening to floor areas ratio. The methodology employed is the multi-stage sampling procedure where houses are sampled from sampled streets, and a household head sampled from each house, such that the perception of residents and evaluation of window and floor areas ratio are both carried out on the same household and house, respectively. The result shows that residents’ satisfaction as well as window to floor areas decreases with residential density zones.
Keywords: Body Comfort, Body Heat, Natural Ventilation, Perception, Satisfaction, Warm humid