Investigation of Hydrothermal Performance of Fibrous Thermal Insulation Materials

Abstract

The hydrothermal performance of fibrous thermal insulation materials is dictated by the response of the system to combined heat, air and moisture fluctuations produced by exterior and interior conditions that exist on either side of the materials. This paper reports on experimental results to assess the drying and wetting rate of fibrous thermal insulation materials in close contact with various combinations of sheathing. Fibrous thermal insulation material, such as mineral wool, was used for investigation. Full-scale specimen of structure was installed in climatic chamber. A median divider separates the specimen in two equal areas: a specimen with sheathing and a specimen without sheathing (reference measurement). Both specimen sections were instrumented to allow direct comparison of the hydrothermal performance. Observations from the full-scale specimen showed that there is a risk moisture accumulation in wall structure, because the water vapour permeability of external layer of fibrous thermal insulation material plays the significant role. According to the results, the R-value decreased 15 % from initial level while moisture content of the external layer of mineral wool increased 10 %.