Indoor air humidity variations and its effects on the moisture performance of building envelope

With the current enhancements moisture engineering analysis of building envelope structures becomes a critical design element. Building envelopes design is often modeled using advanced hygrothermal models and customized for particular interior and exterior environmental loads. This is always conducted by assuming interior environmental conditions that are decoupled by the contributions of the envelope itself. This paper presents the results of whole building hygrothermal simulations, its effects on the indoor air conditions and on the building envelope. The hygrothermal performance of two different rooms with the same thermal and moisture loads is presented. The results show that materials with hygroscopic capacity have the ability to improve the performance of building envelope structures even to such level that condensation and mold growth conditions are eliminated. A state of the art hygrothermal modeling analysis is used to quantitatively assess the performance of both hygroscopic capacity and indoor inhabitant moisture generation.