earticle

영어

This study investigated how building floor area and occupant density affect heating and cooling energy demand in office buildings. Energy simulations were conducted using DesignBuilder for an office building in Seoul, Korea, covering nine floor area cases (2,500~62,500m²) at two occupancy densities (0.0538 and 0.1110people/m²). Results showed that unit floor area energy demand decreased nonlinearly with increasing building size, a trend consistent across both occupancy conditions. Cooling energy (64.87%~88.93% of total energy demand) decreased as floor area increased, while heating energy (11.07%~35.13%) increased, indicating opposing responses to building scale changes. Occupancy density mainly influenced the magnitude of cooling and heating energy demand, while the overall trend was largely governed by building floor area. Analysis by exterior zone ratio revealed that cooling energy demand decreased linearly as the exterior zone ratio was reduced, whereas heating energy demand increased in a nonlinear manner. These results suggest that solar heat gain and heat exchange through the building envelope play a more influential role than internal heat gains in determining overall building energy demand. The findings provide quantitative insight for optimizing building scale and occupancy conditions in office buildings to improve energy efficiency.