Thermal performance of a new low-cost ventilated load bearing masonry with wood-cement blocks

The present paper regards the proposal of an innovative low-cost ventilated load-bearing masonry using a new prefabricated dry-laid formwork wood-cement block with external interconnected holes forming a ventilated cavity. The aim of the work was to verify the performance of this solution by experimental and numerical comparison with other traditional and ventilated walls. To that end, an experimental campaign was carried out in summer on a simplified prototype involving the reproduction of the external ventilated cavity and the simultaneous measure of a ventilated cladding currently used. Numerical calculations on measure-calibrated models allowed to compare surface temperatures and heat fluxes for several ventilated and non-ventilated configurations. The results demonstrated that the proposed wall has a very high attenuation attitude on the crossing heat flows thus reducing summer gains. Moreover, the closing of the ventilation openings in winter and the use of the cavity as a still air gap also reduces the cold period dissipation. The costs are halved with respect to a traditional ventilated solution for the absence of the metal substructure.