EVALUATION OF PASSIVE COOLING STRATEGIES USED IN SELECTED UNIVERSITY SENATE BUILDINGS IN TROPICAL SAVANNAH CLIMATE OF NIGERIA

Purpose: In Nigeria’s tropical savannah climate marked by high temperatures and intense solar radiation university senate buildings struggle to maintain thermal comfort without excessive energy consumption. This study evaluates how passive cooling strategies contribute to energy efficiency and comfort in selected senate buildings. The aim is to assess the effectiveness of passive cooling applications in Ahmadu Bello University (Zaria), University of Abuja, and Federal University of Agriculture Makurdi.

Design/methodology/approach: A qualitative case study approach was adopted. Data were collected through on-site observations, architectural plan reviews, and cooling audits. Assessment focused on three passive cooling categories: heat prevention (orientation, shading, landscaping, reflective colors), heat modulation (insulation and thermal mass), and heat dissipation (natural ventilation). Each building’s performance was scored based on observed design features and cooling strategies integrated into their architectural layouts.

Findings: Results reveal varying levels of passive cooling effectiveness across the buildings. ABU’s eight-story senate building performed strongly in shading (21/30) and ventilation (9/10) aided by courtyards, recesses, and airflow channels. UNIAB’s three-story bisected courtyard design achieved balanced performance in orientation (7/10) and insulation (10/15). FUAM’s semi-circular senate building showed strength in landscaping (19/25) but scored low in orientation (4/10) and reflective color use (10/20) due to its circular form and warm-toned external finishes. Overall, the study found inconsistent application of passive cooling strategies, with weaknesses in orientation and reflective surfaces reducing overall cooling efficiency.

Research limitations/Implications: The study is limited to three case buildings within Nigeria’s tropical savannah region, which may affect broader generalization. Performance scores were based on qualitative assessments and visual audits rather than than long-term thermal measurements.

Practical implications: The findings emphasize the need for integrated, climate-responsive design approaches in institutional buildings. Improved alignment of building orientation, wider use of reflective materials, enhanced insulation, and optimized natural ventilation can significantly reduce reliance on mechanical cooling systems. These improvements can lower operational costs, reduce energy consumption, and enhance occupant comfort in university environments.

Originality/value: This study provides actionable insights into the effectiveness of passive cooling strategies in Nigerian university senate buildings, an area with limited empirical documentation. It demonstrates how building form, material choices, and spatial layout interact to influence thermal performance in a tropical savannah climate.