Estimation of VOC emissions from an electric vehicle interior as a function of cabin air temperature using a selected ion tube flow mass spectrometer (SIFT-MS) measurement.

VOC (Volatile Organic Compound) emissions from vehicle interior materials pose a risk to public health. It is important to be able to predict VOC emission factors under varying cabin air temperature conditions. Most previous studies have either measured VOC emissions under thermal steady-state conditions or reported time-averaged emissions across changing cabin temperature conditions. This study aimed to determine VOC emission factors using real-time VOC concentrations measured by a SIFT-MS (Selected- Ion Flow-Tube Mass Spectrometer), in conjunction with varying cabin air temperatures under different vehicle HVAC (Heating, Ventilation, and Air Conditioning) conditions. The results show that a psuedo-thermal equilibrium condition is achieved in the vehicle cabin during gradual temperature increases under direct sunlight, and that the temperature-dependent VOC emissions measured by SIFT-MS agree well with a theoretical model. The method developed in this study provides an efficient approach for quantifying VOC emissions across multiple vehicles of varying ages, enabling a more comprehensive understanding of VOC emissions from vehicle cabins.