Comparative Analysis of Glare Indices in indoor Environments Affected by Reflected Sunlight

The increasing use of highly reflective building facades in urban areas has intensified concerns over reflected sunlight glare, yet existing glare assessment methods remain inadequate. This study employs a grid-based simulation approach to analyze reflected sunlight distribution in indoor environments and evaluates the effectiveness of established glare indices (i.e., DGP, DGI, UGR, CGI, VCP).

Statistical analysis reveals that vertical illuminance exhibits a weaker correlation with DGP in reflected sunlight conditions (R² = 0.153) compared to non-reflected conditions (R² = 0.746). The findings highlight the limitations of conventional glare indices in assessing reflected glare and underscore the need for a refined evaluation framework.