Evaluation of Greenwalls Efficiency for Building Energy Saving

Abstract

The research moves from thermo-hygrometric data collected during a campaign to monitor energy exchanges at “Building F92” ENEA ‘La Casaccia’, with particular reference to the sections of the building facing south-east, south-west, screened by a green wall. In spring 2018, ENEA installed many sensors to detect parameters such as air temperature, internal and external surface temperature of walls, solar irradiation, wind speed, on the one hand, to validate the reliability of the parameters that can be extrapolated from the critical analysis of data, on the other to derive indications for a possible schematization of the contribution offered by the green-wall to the improvement of the conditions of indoor comfort. The research focused on the interpretation of the values measured by the sensors for the validation of simplified calculation models available in bibliography. The analysis allowed the extrapolation of data useful for the calculation of the Kv-parameter, the so-called “green factor”, an index describing the contribution to indoor cooling offered by the green-wall. The evaluation of the Kv-parameter demonstrates the substantial contribution of the green-wall to the reduction of the energy flux entering the opaque wall.