| It is an effective way to solve the humidity-related problems that making full use of the humidity-controlling performance of building materials and a room itself adjusts indoor humidity,via moisture environment designs of new buildings,as well as moisture performance evaluations and moisture environment renovation designs of existing buildings.The tests and calculations of the humidity-controlling performances of materials and a room are the basis for this work.But they cannot be applied in engineering practice due to the reasons including unavailable hygrothermal properties of the materials and complicated calculations.Meanwhile,the existing testing environment is inconsistent with the actual environment.There are no in-depth and sufficient studies about some problems,such as how to use the testing results of standard conditions to predict and evaluate the moisture ad-/desorption performance of materials in the actual and variable environment.Based on these points,through the comprehensive methods of theoretical analysis,numerical simulation,laboratory test and field test,this paper improves the existing moisture ad-/desorption calculation model and the solution method,and systematically proposes novel methods for engineering tests and calculations of the humidity-controlling performances of materials and a room.The following work is carried out,and new knowledge is gained:(1)Through extensive researches,four typical materials(i.e.,gypsum board,cement mortar,medium fiber board,polyester fiber acoustic board)are determined as the research objects by considering material category and moisture ad-/desorption performance in this paper.Through literatures and standard researches,seven actual environmental conditions closely related to the moisture ad-/desorption performances of materials(i.e.,moisture production,material volume ratio,environmental humidity,environmental temperature,humidity pattern,specimen thickness,environmental airflow velocity)are determined,based on which,simplified and typical actual environmental conditions are proposed.(2)Given the limitations of the existing EMPD(Effective Moisture Penetration Depth)models and the traditional calculation method,a modified EMPD model is proposed by accurately dividing the calculation region,correcting the effective moisture penetration thickness expression,and building the dynamic relationship between material properties and humidity based on the inverse method.Through comprehensively researches of numerical simulation,laboratory test and field test,it is verified that the prediction accuracy of the modified EMPD model on the humidity-controlling performances of materials and a room under various actual conditions is significantly improved,compared with that of existing EMPD models.The average absolute deviation,relative deviation,and overall precision index for predicting air humidity are 0.9% RH,2.4% and 0.992,respectively.(3)A novel integrated method of engineering tests and calculations on the moisture ad-/desorption performances of materials is proposed for engineering applications.Through the verification from the self-developed testing platform,it is confirmed that the novel method can accurately predict the moisture ad-/desorption performances of four common building materials under seven common changing environmental conditions and the synergistic existing condition of multiple materials.The average absolute deviation,relative deviation,and overall precision index for predicting environmental humidity are 0.7% RH,3.1% and0.995,respectively.Meanwhile,compared with the existing methods,the novel method has outstanding advantages of reasonable testing conditions,wide application range and strong engineering feasibility,which can provide strong supports for the evaluation,selection,and optimization of the moisture ad-/desorption performances of materials in new buildings.(4)A novel integrated method of engineering tests and calculations on the moisture buffering performance of a room is proposed for engineering applications.Through the verification from the self-developed system,it is confirmed that the novel method can accurately predict the moisture buffering performance of an actual room under multiple changing environmental conditions.The average absolute deviation,relative deviation,and overall precision index for predicting indoor humidity are 1.4% RH,2.4% and 0.984,respectively.Meanwhile,compared with the existing methods,the novel method has outstanding advantages of strong engineering feasibility,which can provide strong supports for the current moisture buffering performance evaluations and the renovation designs of moisture environment in existing buildings.The contributions of this paper are helpful to enlarge the application range of hygroscopic materials,to improve the application effect,to reduce building energy consumption under superior habitat environment,and to provide theoretical basis and technical supports for the evaluation,design,and improvement of building moisture performance in China. |
