Moisture penetration in a chair seat as a response to daily RH variations in the indoor air

In the indoor environment there are a number of materials with potential to act as moisture buffers including both building materials and furnishing materials. For daily moisture variations in the indoor air furniture with upholstery can play an important role as moisture buffers. Material properties and calculation models describing the response to moisture variations in the ambient climate for these material combinations are limited. In this project the moisture properties for a chair seat with a wool fabric and plastic foam padding were determined. The moisture penetration in the chair seat was measured using small temperature and relative humidity sensors. A numerical calculation model describing the step-response as well as the response to ramp variations is described. A comparison between measurements and theoretical calculations was performed. The difficulties with determination of material properties for highly permeable materials are also discussed as well as suitable methods and special considerations