Optimal Skylight-to-Roof Ratio in Central Atriums for Thermal Comfort: Case Studies Yazd and Tabriz Cities

Atria plays a vital role in design of modern office buildings, significantly influencing indoor thermal comfort. In hot and arid climates, inadequate skylight design can contribute to overheating thermal discomfort, leading to an increased Predicted Percentage of Dissatisfied for occupants. To enhance thermal comfort, it is crucial to establish an optimal skylight-to-roof ratio (SRR). In cold and dry climates, selecting the appropriate dimensions for skylights can also help reduce the energy consumption of heating systems. Central atria are commonly incorporated into office buildings, though their energy performance varies by climate zone. The research method employed in this study involved modeling case studies using the Grasshopper plugin environment within the Rhino software. Thermal comfort simulations were conducted using the Legacy Honeybee plugin, which provides accurate assessments of indoor environmental conditions. This study investigates the relationship between atrium skylight to roof ratio (SRR) and thermal comfort parameters, including Environmental Conditions (Env-conds), Standard Effective Temperature (SET), Thermal Comfort Percent (TCP), Heat Sensation Percent (HSP), Cold Sensation Percent (CSP), and Operative Temperature (TO). The research was conducted in Yazd and Tabriz (Iran) for different seasons, and the results showed that Yazd’s optimal SRR for thermal comfort is 20%, while in Tabriz, it reached 70%. Yazd faces discomfort during summer due to elevated temperatures, necessitating smaller skylight areas to mitigate overheating; conversely, Tabriz benefits from larger skylights, particularly in winter, to maximize solar heat gain. These findings underscore the importance of optimizing skylight design to improve thermal comfort in office buildings.