Effectiveness of Passive Solar Shading for Energy Efficiency in Hotel Buildings in Abuja, Nigeria

This study examined the effectiveness of passive solar shading in reducing cooling energy demand and improving thermal comfort in hotel guestrooms in Abuja, Nigeria. The specific objectives were to: i) determine the pre-test and post-test annual cooling electricity consumption of guestrooms in the experimental (shaded) and control (unshaded) groups; and ii) ascertain the pre-test and post-test annual thermal discomfort hours of guestrooms in the two groups. Two hypotheses were formulated and tested at the 0.05 level of significance. The study adopted a computational pre-test, post-test control group experimental design. Forty representative hotel guestroom models, stratified by orientation, were simulated hourly for a full year under Abuja climate conditions, and 20 were randomly assigned to receive shading devices (experimental group) while 20 were left unchanged (control group). The instrument for data collection was a purpose-built hourly thermal simulation model. Analysis of Variance (ANOVA) was used to test the two hypotheses at the 0.05 level of significance. The findings revealed that the post-test mean cooling electricity of the experimental group (54.4 kWh/m²/year) was significantly lower than that of the control group (64.7 kWh/m²/year), F(1, 38) = 18.70, p < .001, and that annual discomfort hours were also significantly lower in the experimental group (1,344 against 1,508 hours), F(1, 38) = 33.20, p < .001. Shading reduced cooling electricity by 11.6% and discomfort hours by 9.5% in the experimental rooms, with the greatest benefit on south-facing rooms. The study concluded that passive solar shading significantly improves the energy efficiency and thermal performance of hotel guestrooms in Abuja. It was recommended that orientation-specific shading be integrated into hotel design guidelines and retrofit programmes in Abuja