Comparing the energy efficiency of exterior shading by metal slats and mesh screens in an early phase design exercise for an office building in Bucharest

Abstract

An early phase design exercise for shading a South facade of an office building in Bucharest is presented here. The problem to solve is deciding in a simple and quick way (not using the complicated BSDF approach), based strictly on energy-efficiency considerations, between two options in principle: the first, exterior screens, is much cheaper and the send is unmovable horizontal aluminium slats. The tool used to produce the necessary result quantities by building energy simulation is COMFEN 4.1. The conclusion is positive: if aesthetic reasons are ignored, in Bucharest and very likely many other Romanian cities having a quite similar climate, screens can be at least equally effective in saving energy by South facade shading. As they allow a flexible shading strategy (removing them during some months of the heating season), the energy-efficiency realized by having them on throughout the year can be increased further.