Development of a moisture transfer calculation method of hygroscopic material plate in buildings

摘要

Hygroscopic material could be used to moderate the indoor humidity fluctuation and reduce heating and cooling energy consumption. In order to calculate the moisture transfer between the wall hygroscopic material plate and the indoor air quickly and accurately, a simple moisture transfer calculation method coupling moisture transfer function and Fourier transform is proposed and developed. This paper further presents the analytical verification and experimental validation of this method. The analytical verification shows that the average relative error between the model prediction and analytical results under the periodic sinusoidal and rectangular variations of indoor air humidity are 0.2% and 5.2% respectively. An experiment test rig was established to measure the moisture sorption of hygroscopic material plate taking silicate calcium plate as a sample. The chamber climate was controlled as expected and two typical real office climates with different moisture load schedule were simulated. Compared with the experimental measurements, the average relative errors of the moisture flux between the model prediction and the measurement are 10.7% for Case 1 and 12.1% for Case 2 respectively. The proposed method has also been validated by published experiment measurements and shows a good accuracy as well as high computationally efficiency. This simple method can be easily applied on moisture sorption calculation of hygroscopic materials.