Simulação Numérica do Comportamento Higrotérmico de Fachadas

• Author(s): Silvano Pires Rites
• Date: 2009
• Persistent ID: https://hdl.handle.net/10216/96264
• Origin: Repositório Aberto da Universidade do Porto
• Subject(s): Engenharia civil; Civil engineering
• Document Type: Master thesis
• Language: Portuguese

Description

The degradation of the exterior aspect of the façades due to the growth of microorganisms, seaweed and fungus is, at present, a much more frequent pathology in construction, without an easy solution and efficient recovery. It is known that during the night the walls cool down, brought about by the radiative cooling, and that, depending on the weather, the wall's composition and the orientation of the amount of condensed flow are totally different. The exterior superficial condensations in façades are one of the causes of the growth of microorganisms, seaweed and fungus, in this way, knowing that the dew temperature corresponds to value in limit, at a point in which condensations are formed in the element, and if the drying process isn't fast enough, there will be a high concentration of humidity in the exterior face of the parament which, in the long run, will be favourable to the display of these substances. In the attempt to study the behaviour of these façades with regards to the occurrence of superficial condensations, the procedure was to use the automatic estimate program "WUFI Pro", which is able to evaluate exterior superficial temperatures of the different types of façades, under different conditions. In this way, throughout the present study and with the objective of learning the factors which most influence the superficial condensations in façades, which will subsequently show below the form of microorganisms, seaweed and fungus, varying and combining different parameters, namely the type of constructive solution and the respective localization and direction of the element. As a means of allowing a rapid interpretation of the results obtained and a global perception of the risk of condensation occurrence in each of the situations analyzed, presents itself as a conclusion to the study, in which it is possible, through colour gradation, to see which is the probability of condensation occurrence in each of the constructive elements analyzed, when prone to different climatic conditions and orientation. KEYWORDS: Façades, Hygrothermic behaviour, Radiative cooling, Superficial condensations, Development of microorganisms.