A new method for determining the formaldehyde emission characteristic parameters of building materials: Single airtight emission method

The volatile organic compound (VOC) emissions of building materials are represented by three parameters: the initial emittable concentration (C₀), diffusion coefficient (D), and partition coefficient (K). Accurate measurement of these three parameters is key to the reasonable prediction and control of VOC emissions from building materials. In this study, a single airtight emission (SAE) method for determining the three emission parameters of building materials is proposed. Based on the dynamic analysis of the normalized relative sensitivity coefficient of the characteristic parameters in an airtight environment, the three parameters could be determined by piece-wise fitting of the experimental data. This method requires only a single airtight emission experiment for building materials, and the experimental time is short (≤36 h). C₀, D, and K can be simply calculated by nonlinearly fitting of the experimental data. It demonstrated some significant improvements towards better simplicity and accuracy compared to previous methods. The emission parameters of formaldehyde in the four types of building materials were determined following the SAE method, and the predicted values agreed well with the experimental values under various environmental conditions. Additionally, the possible sources of errors using this method were analyzed, and the influence of the initial hypothesis on the results was also discussed to further verify the feasibility and accuracy of the method. The SAE method proposed in this study can efficiently and accurately measure the formaldehyde emission parameters of building materials, and is suitable for application in engineering, requiring a short time and simple operation.