Balancing daylight in office spaces with respect to the indoor thermal environment through optimization of light shelves design parameters in the tropics

The study aims to investigate the preferred daylighting availability ranges for the best visual and thermal comfort in office workspace through optimal modifications light-shelve parameters, grounded on parametric design and optimization, with a focus on its visual and thermal indices. To identify the final optimal solutions, single and multi-optimization scenarios were used. The findings revealed that optimizing for a single objective might obstruct the attainment of other goals. In other words, the first scenario, optimization only for daylight availability, results in an increase in temperature. While optimizing for indoor thermal performance solely, none of the preset daylight availability acceptance requirements were met. However, multi-objective optimization solutions were the final optimal solutions nearest to the ideal. Final optimum solutions of the best design parameters of light shelves can improve the total average of daylight availability by 56.25%, 50.63%, 57.50% and 71.88%, and the indoor thermal performance was improved by decreasing the average temperature for thermal environmental performance indicators by 4.15%, 3.27%, 3.17% and 4.76%, respectively, in March, June, September and December. The study concludes that daylighting levels of 500 lux to1300 lux provide the best range of optimal daylighting for visual and thermal comfort indicators for office spaces in the tropics.