Energy renewal of INA-casa heritage, relevance of moisture transport

The energy renewal of the INA‐Casa Program buildings is guided by the observations of many values expressed about their construction, architectural typology and urban fabric morphology. A study of the energy renewal approaches has been carried out regarding both the way to improve insulationand the heat and moisture transfer analysis approaches needed for the right efficiency check. The study has been carried out on the buildings of the first seven-years period of the Program, which already espoused the framed structure with masonry infill walls and are characterized by a specific quality in the constructive techniques with regards to architecture and building typologies. The analysis of the buildings has confirmed the high thermal transmittance. As is well known, any change of the thermal behavior of a wall modifies the vapor saturation pressure within. This is usually accounted for through the check for interstitial condensation, done together with that of thermal transmittance. In this paper the results of a screening of the possible energy renewal interventions on a significant INA‐Casa building, depicting which approaches need a complete check of both effective insulation and moisture transfer and which are not recommended as, even though they could be effective by the thermal point of view, they lead almost surely to interstitial condensation. The coupled vapor pressure and temperature fields are studied numerically, by solving the linear partial differential equations through finite elements method.