Multivariable Analysis of Indoor VOC Dynamics in a Smart Urban Building: Advancing Evidence-Based and Health-Centered Air Quality Management

This study investigates the dynamics of indoor volatile organic compounds (VOCs), including formaldehyde, xylene, and toluene, within a newly constructed smart urban building in Bangkok, Thailand. It aims to identify key determinants of air quality and to support datadriven strategies for healthier indoor environments. A total of 120 indoor air samples were collected from multiple zones and timeframes, considering building usage patterns, air conditioning operation, and environmental factors such as temperature, humidity, and air velocity. Statistical analyses revealed that air velocity and usage time significantly influenced VOC concentrations, while the time period was a critical factor for formaldehyde levels. Toluene concentrations exceeded the ACGIH guideline (20 ppm) in 13% of samples, and formaldehyde levels surpassed NIOSH thresholds in all samples, indicating potential exposure risks. Higher ventilation rates were linked to reduced pollutant accumulation, particularly during peak occupancy. Strong correlations between toluene and xylene also indicated shared emission sources. Although most values remained within regulatory limits, some exceeded health-based guidelines. These findings highlight the complex interactions among building operations, environmental conditions, and chemical exposure, and suggest targeted ventilation scheduling, particularly early-morning activation, to reduce VOC peaks. The study provides a practical framework for designing adaptive ventilation systems and developing guidelines to improve indoor air quality in new buildings. Insights from this research can inform future policy, urban planning, and smart building design aimed at reducing health risks and enhancing environmental resilience.