Hygrothermal behaviour and simulation in buildings

Energy efficiency and comfort are two new critical expectations of the modern building owner. With the recent technological advancement in all fields of engineering, buildings are also expected to be durable. Premature or accelerated ageing with the associated damage due to inappropriate design or operation is simply no longer acceptable. To prevent moisture-induced damage in buildings, hygrothermal simulation tools should be used to design envelope parts with good performance. The building envelope responds to the dynamic exterior and interior environmental loads. Temperature and humidity conditions in building structures must not exceed certain thresholds for effective moisture control. This has been recognized recently ba a number of standards organizations in Europe and North America that deal with hygrothermal analysis. This chapter presents an overview of the fundamentals, the required material and construction input data, the required exterior and interior environmental loading, and the description of the output results from the heat and moisture transfer models. A few example cases are also presented that demonstrate how moisture problems may be investigated and how better design alternatives can become possible using hygrothermal analysis. Finally, the limits of the current state-of-the-art simulation models are described and futures trends and developments are discussed.