Energy Efficiency of Ventilated Façades: Residential Buildings, Alicante, Spain

Abstract

Ventilated façades with external thermal insulation contribute to the construction, in certain climatologies, of a great energetic efficiency in the thermal envelope of the building. This façade allows to eliminate the thermal bridges, reduce the energy demand and improve the level of comfort. These pages describe the research carried out in an isolated residential block in the city centre of Alicante. The house has two façades with different orientation: a ventilated façade (north) and a conventional façade (south). The first one is solved with two sheets of brick, the air camera, the external continuous insulation, the ventilated chamber and the pieces of porcelain stoneware to the outside. The conventional one consists of two sheets with intermediate thermal insulation. The outer sheet is composed of facing brick and the inner sheet by hollow brick of minor thickness with plaster. This system was correct according to the norm NBE-CT-79, but it has been shown that it is insufficient to reach the levels of habitability and the comfort of the current society. The two façades, as well as their adjacent living spaces, have been monitored over a period of two years. Internal and external temperature and humidity, solar radiation, air velocity in the ventilated chamber and surface temperature of each of the material layers of the sections have been obtained. A thermographic study of the two chambers was carried out to determine the thermal bridges and the air infiltration. Through the use of energy simulation tools, comparative results of some parameters have been obtained in both constructive solutions, such as thermal transmissions, average radiant temperatures, operating temperatures or energy demands. By that, we can obtain the conclusions of thermal comfort levels and energy savings of ventilated façades.