Active building envelopes: An integrated solution for solar cooling and heating

Solar thermal collectors are traditionally applied on roofs of low buildings to cover the domestic hot water and heating demand. Nevertheless, for high buildings the roof surface is not sufficient to satisfy such demands and consequently the entire envelope should be exploited. In this study an innovative system of solar thermal façade has been designed for the application on an existing apartment tower in order to satisfy the energy needs for winter heating and summer cooling. The tower, built in the 80s, is placed in Sicily, a region which may be considered representative of mild Mediterranean climate. The proposed system consists of evacuated tube solar collectors assembled on modular panels, designed to reduce the overall costs. Also the aesthetic instances have been properly considered, taking care of both the design and the composition of the panels on the façade. Depending on specific requirements, each panel can be flexibly equipped with optional accessories, such as insulation layers, sun-tracking mirrors, PV-modules, maintenance and cleaning devices. Results show that this active façades can be effectively used in the case study, that is representative of high rise residential buildings, but it may have convenient application also on new constructions. Keywords: active façade; evacuated tube solar collectors; Mediterranean climate; modular panels.