Mathematical Model for Enhancing Passive Indoor Thermal and Visual Comfort in Double-Banked Office Buildings in the Temperate Dry Climate of Nigeria

Many researchers have differed on the optimum values of Passive Indoor Thermal and Visual Comfort (PITVC) determinants in tropical climates. The study is aimed at developing a mathematical model for enhancing PITVC in singled-banked midrise office buildings, during the activity period (8 am to 5 pm), in the temperate dry climate of Nigeria. It was achieved by evaluating the effects of Orientation, WWR, R-values, and shading devices on PITVC. A quantitative research design using an explorative design approach was employed in the study as well as an experimental research strategy through simulation method to enhance PITVC. The study used Federal Secretariate building as a prototype of a single-banked office building. The Google Sketch-Up 2022 and OpenStudio simulation tools were used to evaluate the prototype building from January to December 2023. The data generated was analyzed using relevant statistical tools (MANOVA, ANOVA, column charts, graphs, and tables). The findings revealed that the best WWR for visual and thermal comfort are 45% and 15% respectively while the compromise value was 45%. the best values of projection factors for visual and thermal comfort are 0.35 and 0.6 respectively while the compromise value was 0.5. It was also noted that the R-value of external wall insulation material does not affect the visual comfort of an office building but affects operative temperature as well as relative humidity as the optimum value was found to be 3.61 m2·K/W.  The mathematical model was developed as as   A= - 47.22 + 174.22WWR - 85PF + 6.33R…….1  Where A is orientation, WWR window-to-wall ratio, PF projection factor, and R is the R-value of the external wall materials.