Air cavity performance in Opaque Ventilated Façades in accordance with the Spanish Technical Building Code

Abstract

The use and study of Opaque Ventilated Façades (OVF) has considerably expanded in recent years as an efficient envelope option when hoping to reduce cooling thermal loads for buildings. This is due to the solar protection provided by the outer layer and the ventilation from the air cavity. However, the actual situation in the air cavity of OVF buildings is usually very different from the theoretical studies, which do not consider the fixing systems of the outer layer regularly arranged inside the air cavity. This information is crucial to understand and validate predictions of the efficient behaviour of the system. Therefore, the objective of this work is to classify and analyse the performance of the air chamber in OVF existing buildings in Barcelona in accordance with current building regulations. Methodology Twenty-one buildings were surveyed and classified and the air movement and temperature inside the cavity was measured in ten buildings. Conclusions The findings show that although the Technical Building Code of Spain regulates the air cavity ventilation according opening minimums per linear meter, air inlet and outlet openings have the greatest influence on air cavity ventilation, even more so than open joint surface of the outer

Experimental Validation of a Numerical Model of a Ventilated Façade with Horizontal and Vertical Open Joints

“…Scientific literature about OJVFs is very scarce, although there are some papers analysing certain characteristics also applicable to these façades, for example, studies evaluating different panel materials (ceramic [56], clay, stone [57], or even metal [58,59]) or the effect of the climate [60]. There are some articles considering the influence of the geometry, although they do not provide specific data [61,62].…”

Mejoras en el desempeño energético de edificios en verano mediante la integración de envolventes ventiladas en fachadas norte y cubiertas. El caso de Mendoza, Argentina

“…En relación a las características constructivas del sistema de fachada ventilada, se ha demostrado que el incremento de la apertura de aire en la cámara implica mayores ahorros energéticos para climatización (Patania et al, 2010). De igual manera, el relevamiento y el monitoreo de la velocidad del aire de edificios construidos con fachada ventilada en la ciudad de Barcelona, mostró que más del 70% de los casos contaba con la cámara de aire cerrada en sus aperturas superiores e inferiores, imposibilitando el correcto desempeño de un sistema de envolvente ventilado (Balter et al, 2019). Los resultados del presente trabajo han sido simulados considerando las intervenciones en la envolvente en funcionamiento, lo que significa que, en la práctica, deberá controlarse que no se cierren las aberturas superiores e inferiores de las fachadas ventiladas o las aperturas laterales de las cubiertas ventiladas.…”

Desempenho térmico de fachadas ventiladas opacas

“…In general, studies on the performance of ventilated facades tended to analyze the air inlet and outlet openings in more depth. Balter et al (2019); Petritchenko et al (2017); Marinosci, Semprini and Morini (2014) compared closed and open joints and found better results when the joints along the facade are closed and the air opening occurs only through the lower and upper portions of it. In these authors' studies, open joints reduce the thermal load reduction capacity of ventilated facades during the summer, as the buoyancy effect is greater without open joints.…”