Investigating the early-stage emissions of formaldehyde/VOCs from building materials and their influencing factors.

Abstract

As urbanization accelerates, the issue of pollutant discharge from building materials has become the focus of public attention. Conducted in a ventilated environmental chamber, the experiments investigated the emission characteristics of VOCs from dry and wet building materials, focusing on the influencing factors, such as temperature, relative humidity (RH), ventilation, and seasonality. The impact of influencing factors was quantified using a one-factor-at-a-time control method. This study establishes that environmental factors - temperature, RH, air exchange rate (AER), and seasonality - significantly influence VOC emissions from building materials. Elevated temperature and humidity consistently increase emission rates and concentrations, while higher AER reduces indoor VOC levels. Emissions peak rapidly upon material installation, decline sharply, and stabilize within predictable ranges. Seasonal variations show summer (high temperature/RH) yielding maximum emissions, contrasting with winter minima. Dry and wet materials exhibit similar emission trends, though temperature exerts a stronger effect on formaldehyde release from dry materials, while RH elevates peak and stable concentrations for wet materials. AER demonstrates dual effects: promoting initial emissions while diluting concentrations long-term, warranting further investigation. The C-history method efficiently determines initial emittable concentrations, and validated predictive models accurately forecast steady-state emissions across varying conditions. These models reliably estimate long-term pollutant levels using short-term data, proving valuable for indoor air quality assessment, material selection, and ventilation design. The study provides valuable insights into the practical significance of temperature, RH, ventilation, and seasonality on the emission rates of formaldehyde and TVOC from building materials.