{"id":808,"date":"2014-05-06T15:05:00","date_gmt":"2014-05-06T15:05:00","guid":{"rendered":"http:\/\/incafust.org\/bloc\/?p=808"},"modified":"2016-11-28T16:57:31","modified_gmt":"2016-11-28T16:57:31","slug":"computer-simulation-study-on-fire-behaviour-in-the-ventilated-cavity-of-ventilated-facade-systems","status":"publish","type":"post","link":"https:\/\/www.incafust.cat\/?p=808","title":{"rendered":"Computer-simulation study on fire behaviour in the ventilated cavity of ventilated fa\u00e7ade systems"},"content":{"rendered":"

ABSTRACT<\/strong>
\nFire spreading through the fa\u00e7ades is widely recognized as one of the fastest pathways of fire spreading in the buildings. Fire may spread through the fa\u00e7ade in different ways depending on the type of fa\u00e7ade system and on the elements and materials from which it is constructed. Nowadays the trend in architecture is towards a growing usage of lightweight construction systems that are quick to install, versatile and have a high technical and aesthetic value. The ventilated fa\u00e7ade has all these characteristics as well as providing a good performance from hygrothermal point of view.
\nVentilated fa\u00e7ades are multilayer systems whose main feature is the creation of an air chamber of circulating air between the original building wall and the external cladding. The \u201cchimney effect\u201d in the air cavity is a mechanism that improves the fa\u00e7ade\u2019s thermal behaviour and avoids the appearance of moisture from rain or condensation. However, in an event of fire, it may contribute to the quickest spreading of fire, representing a significant risk to the upper floors of a building. This study deals with some aspects of fire propagation through the ventilated cavity in ventilated fa\u00e7ade systems. Also we review the provisions stipulated by the Spanish building code (C\u00f3digo T\u00e9cnico de la Edificaci\u00f3n, CTE) [1] to avoid fire spreading outside the building.
\nThe results highlight the importance of the use of proper fire barriers to ensure the compartmentalization of the ventilated cavity, as well as the use of non-combustible thermal insulation materials, among others. In addition, based on the results, it might be considered that the measures stipulated by the CTE are insufficient to limit the risks associated with this kind of fa\u00e7ades systems. The study has been performed using field models of computational fluid-dynamics. In particular, the Fire Dynamics Simulator (FDS) software has been used to numerically solve the mathematical integration models.<\/p>\n

\"1.<\/a>
1. Support (wall, column, slab, etc)
2. Substructure\/ fixing system
3. Insulation
4. Air chamber (Cavity)
5. Cladding<\/figcaption><\/figure>\n

Ventilated fa\u00e7ades are multilayer systems whose main feature is the creation of an air chamber of circulating air between the original building wall and the external cladding.<\/p>\n

The pressure difference between the air in the cavity and outside leads to the creation of an airflow known as the “chimney effect<\/em>“, which eliminates humidity in wet conditions and prevents condensation. The use of ventilated fa\u00e7ades offers different advantages from the higrothermal point of view. However, in terms of fire safety, the chimney effect poses a risk, because the ventilated cavity may provide a pathway for the fire to spread quickly.<\/p>\n

Objectives<\/strong><\/p>\n

This study aims to assess fire behaviour and its propagation through the cavities of ventilated fa\u00e7ades systems. In particular, we seek to assess the level of protection provided by the measures stipulated by the CTE. We focus our study on the following aspects:<\/p>\n