Alternately airtight/ventilated emission method: A universal experimental method for determining the VOC emission characteristic parameters of building materials

The volatile organic compound (VOC) emissions of building materials are characterized by three key parameters: the initial emittable concentration (C-0), the partition coefficient (K), and the diffusion coefficient (D). Accurate determination of these three parameters is the basis for understanding VOC emission characteristic and the prerequisite for determining appropriate control strategies. In this paper, an alternately airtight/ventilated emission (AAVE) method for efficient and accurate determination of VOC emission characteristic parameters of building materials is proposed. By switching the airtight/ventilated emission mode of the building material samples, the equilibrium concentration in the airtight state and the dynamic concentration in the ventilation state were measured. K and C-0 can be simply calculated by linear fitting of experimental data. Compared to the multi-emission/flush regression method and the variable volume loading method, the AAVE method requires less pre-adjustment process and has a wide measurement range. Compared to the two remarkably efficient measurement methods, the closed/ventilated chamber C-history methods, the AAVE method requires fewer intermediate parameters, simpler calculation process, and has a better error tolerance to the process data. The formaldehyde emission characteristic parameters of four types of building materials were measured using the AAVE method and verified by independent experiment. The experimental results indicated the reliability of the AAVE method. Finally, an optimized selection method of the ventilation parameters is proposed for adapting to the characteristic parameter measurement of various building material-VOC pairs.