Energy saving and environmental benefits of metal box vegetal facades

The aim of this research work is evaluating energy saving and environmental benefits of vegetal facades in comparison to traditional facades. In order to achieve this objective, a particular type of vegetal facade has been studied and installed in an experimental building. A similar facade without the vegetation layer has also been installed in the same building in order to compare both facade models. All the components of the two experimental facades are monitored by state probes that register temperature data of the layers that conform each experimental closing module in periods of five minutes. In addition, a weather station that has been installed in the same experimental building provides data about solar radiation, humidity, pluviometry, wind speed. Results show that during summer time the temperature of those layers of the facade with vegetation are lower than the one registered in the facade without vegetation. The reason of this fact is that the temperature of the leaves is similar to the one of the air, whereas the outside cladding is overheated due to the action of solar radiation. In the case of winter, the vegetation layer goes on with its role of a solar protection element and this means negative effects for the optimal use of solar radiation in walling. In conclusion, the optimal use of these prototypes of facades according to the climate of Colmenar Viejo (Madrid), whose climatic characteristics are hot summers and cold winters, carries important benefits related to comfort conditions in buildings. The way to optimize the system in winter consists on the incorporation of deciduous vegetation in the facades prototypes.