Abstract
The present paper illustrates the development and validation of an innovative all-in-one timber-based envelope solution for deep building renovation, designated as the "energy and air-fresh distribution kit." This research encompasses the comprehensive engineering process of integrating HVAC systems into prefabricated timber façades and presents the results of numerical and experimental analyses. The façade kit incorporates the innovative HVAC concept that completely replaces the traditional energy infrastructure, including the previous methods of generation, distribution, and heat emission. This integrated approach requires carefully dimensioned components, including the HVAC machinery and associated ductwork into the timber prefabricated façade. One of the main research objective was to embed these elements within the prefabricated timber based elements normally used for the industrialized renovation. Two viable configurations were developed and validated: a façade-integrated system and a parapet-mounted solution. Performance assessment through numerical simulations and laboratory testing on full-scale prototypes demonstrated that the integrated system maintains an equivalent thermal transmittance, comparable to reference façades without integration. While preliminary simulations indicated potential condensation risks under critical boundary conditions, laboratory tests confirmed no condensation formation, with relative humidity remaining below ninety percent at minimum supply air temperatures of fifteen degrees celsius. Several insulation configuration on the VMU (Ventilation Machine Unit) has been evaluated and for instance the addition of a ten millimiters aerogel insulation layer further enhanced hygrothermal performance. The successful integration of HVAC components, despite increasing manufacturing time, demonstrates the feasibility of this solution for real-case implementation. The thermo-igrometrical simulation and testing activities influenced the prefabricated facade element design and engineering, especially in the airducts passage though the timber mullions, and in the localization and integration of the VMU and the distribution elements (Plenum). This research establishes a foundation for future developments in integrated HVAC systems within prefabricated timber façades, suggesting opportunities for optimization in manufacturing processes and material selection while maintaining performance standards.