Assessing energy consumption and operational carbon emission: A case study of office building in Hanoi

Abstract

This study investigated the energy consumption characteristics and associated operational carbon emissions of a specific office building located in Hanoi during the period from Sep 2024 to May 2025. Monthly electricity consumption, technical and operational data were collected through site surveys and engineering drawings. The analysis revealed that energy consumption was strongly influenced by seasonal climatic conditions, with cooling loads driving the increased electricity demand during the warmer months (September – November, 2024 and April – May, 2025). Plug loads were identified as the largest contributor to the total energy consumption of the office building during the study period, followed by air-conditioning systems, outdoor lighting systems, ventilation systems, indoor lighting systems, elevators, and domestic water pumps. The monthly CO₂ emission estimations showed a strong relationship with the monthly electricity consumption, resulting in the elevated operational carbon emission levels during high cooling demand periods. The findings implied that the targeted energy-saving measures such as enhanced operational management and improvements in air-conditioning systems could collectively reduce energy consumption and CO₂ emissions of the office building. This case study contributes valuable insights for building owners and managers, designers, and policy makers aiming to improve the energy and environmental performance of office buildings.