Heat and mass transfer modelling for moisture-related risks in walls retrofitted by timber materials

In this paper, the proposed building renovation solution called e-CLT is investigated in terms of moisture related risks, i.e. the mold growth and the increase in heat losses due to Liquid Water Content (LWC) within building materials. To this aim, dynamic simulations are performed by means of Delphin 6.1, thus including combined heat and mass transfer (HAMT) due to water vapor migration and accumulation. The results show that, although there is no significant risk of mold growth in the e-CLT for climate conditions belonging to Northern Italy, the moisture content within the materials implies an increase by about 10% in the heat losses if compared with the dry case. Furthermore, inaccurate materials properties and boundary outdoor climate conditions can affect the reliability of the results: for this reason, a more appropriate hygrothermal characterization of materials is recommended, as well as the identification of suitable climate dataset, which however are not always available.