Hygrothermal performance of light steel-framed walls

Hygrothermal performance of a new light-gauge steel framed building envelope system has been analyzed using 3-D thermal simulations, 2-D combined heat, air and moisture transfer simulations, laboratory testing in a calibrated and guarded hot box (ISO 8990), weather resistance tests for full-sized structures, corrosion tests and field measurements at experimental buildings in Ylöjärvi, Central Finland. The results show that a modern steel wall structure based on perforated steel profiles performs satisfactorily in the cold climate of Finland. The perforations reduce heat loss along the web of the profile significantly. The field measurements show that no condensation has occurred in the frame system. Temperature measurements and infrared surveys in demonstration buildings show that surface temperatures are sufficiently high to prevent surface condensation or even increased humidity on the surface. According to the calculations, there are no severe corrosion risks in the steel frames in the Finnish climate. The climate, however, has an important effect on the performance, and the structures should be designed with regard to climatic conditions.