Thermal-related occupant behaviors in highrise apartments: Evidence from a large scale survey in Hanoi and Ho Chi Minh City

Abstract

The rapid growth of air-conditioning use in Vietnamese metropolitan areas has become a major contributor to residential energy consumption and peak electricity demand. However, empirical studies focusing on actual user behavior in high-rise apartment remain limited. This study investigates air-conditioning usage patterns and related energy consumption behaviors through a large-scale residential survey conducted in Hanoi and Ho Chi Minh City. A total of 950 valid questionnaires were collected, covering occupants’ characteristics, building’s characteristic and air-conditioner ownership, operating habits, temperature settings, seasonal usage patterns. Quantitative statistical analysis was applied to examine differences in usage behavior across cities, seasons, and occupant characteristic groups. The results reveal distinct behavioral patterns in thermal comfort, especially in air-conditioning operation, variations in usage intensity between hot and transitional seasons. Occupants’ characteristic differences were observed in specific behavior. The findings highlight the critical role of occupant behavior in residential energy consumption and demonstrate substantial potential for energy savings through behavioral adjustments and improved user awareness. This study provides empirical evidence to support energy-efficient building design, occupant centric energy strategies in rapidly urbanizing tropical cities.