Aerogel-based solar thermal facade for space heating and domestic hot water production

This study presents a comprehensive thermal analysis of a patented fa & ccedil;ade concept: an aerogel-based, fa & ccedil;adeintegrated solar-thermal collector designed to simultaneously reduce space heating demand and domestic hot water (DHW) energy consumption. A transient MATLAB model is developed to resolve coupled conduction and radiative transfer across the glazing-aerogel-absorber-concrete assembly and the storage tank. Radiative transport in the strongly scattering aerogel bed is captured using a two-flux formulation, enabling thicknessdependent prediction of solar transmittance; the thermo-optical model is validated against published outdoor measurements with close agreement. Under steady-periodic boundary conditions, the fa & ccedil;ade provides dual functionality by increasing the inner wall-surface temperature (passive space heating) and preheating DHW. Depending on irradiation level, a 2 m 2 fa & ccedil;ade solar collector delivers 0.6-2.16 kWh/day of net heat to the indoor space and 2.1-3.23 kWh/day to the tank. Parametric simulations quantify trade-offs associated with aerogel thickness, mass-flow rate, wall thermal conductivity, and draw-off profiles. Building-scale performance is evaluated via MATLAB-EnergyPlus co-simulation for a representative singlefamily house in Nice (France). Compared with an identical reference house where the same fa & ccedil;ade area is modelled as a conventional insulated wall (no solar collector) and DHW is supplied by the auxiliary electric heater only, a 6 m 2 aerogel solar fa & ccedil;ade reduces seasonal space heating demand by 24 % and auxiliary DHW energy consumption by 58 %. The results highlight the potential of aerogel-based solar fa & ccedil;ades to combine high insulation with effective solar heat harvesting for space and water heating.