Daylighting Performance Assessment of Side-Lit University Lecture Theatres in the Hot-Humid Climate of Makurdi in Nigeria

Abstract

Daylighting is required to enhance visual comfort; whereas its illumination provides renewable functional interior lighting for specific programmes. Hence, this study examines the levels of daylight illumination for teaching and learning in two lecture theatres each located at the Federal University of Agriculture Makurdi (UAM) and Benue State University Makurdi (BSU) in Makurdi, Nigeria. The two buildings selected for the daylighting performance employed post-occupancy evaluation approach. A digital camera was employed to take photographs, whereas digital light meters were employed to evaluate the levels of illumination on the work plane. The results showed that 80% of the study space has inadequate indoor daylight illumination quantity and distribution as well as poor daylight ratios of 1.1and 0.9 for UAM lecture theatre and BSU lecture theatre, respectively Hence, the lighting conditions in the selected buildings fall short of the international lighting benchmarks (IESNA). Therefore, a pragmatic daylight design strategy is required to enhance daylight levels in the lecture theatres for energy-saving and visual comfort as well as onwards design and fusion in the national building code.

Daylighting Evaluation and Optimisation of Window to Wall Ratio for Lecture Theatre in the Tropical Climate

“…The overcast sky denotes the worst sky scenario where the skydome's external illuminance is considered uniform. The desirable daylight factor for spaces such as lecture theatres is typically between 1 to 5% and is for daylight utilization [10], as shown in Table 2. Other static metrics include a view to the outside, avoidance of direct sunlight, uniformity, and illuminance [26].…”

“…D.F. performance range used in the experiment was between 1-5% as performance criteria for tasks in the lecture theatre [10].…”

“…More so, optimization provides the possibility to explore multiple design variables and objectives to select the value of variables that improve the desired goal without harming the others [9]. The advocacy for sustainable passive design strategies to achieving optimisation is desirable in building like lecture theatre [2,10].…”

“…challenges in lecture theatres, lecture rooms, and other pedagogic spaces. Thus, it was provoking the need to explore and adopt strategies for enhancing the quantity and quality of daylight in these spaces [10][11][12]. It is well established that daylighting has a significant value of 30 to 70 percent in energy reduction from electrical light consumption [13,14].…”

“…More so, the daylighting rule of thumb stipulates 2.5H for daylighting performance where H is the height of window opening relative to the work plane, and it is the possible horizontal depth of significant daylight penetration to the building interior from the sidewall 2. Lighting Performance Indicator adopted from [10].…”