International building legislation is setting stronger and stronger requirements for the energy performance of buildings. The most recent example is the Energy Performance of Buildings Directive in the European Union. The improved energy performance of buildings can't be achieved by additional insulation or more effective building systems only. A major influence factor on the energy quality is the ventilation technology and also the airtightness of the building.
The hygrothermal behavior of the building envelope affects the overall performance of a building. There are numerous tools for the simulation of the heat and moisture transfer in the building envelope and also whole building simulation tools for energy calculations.
In tropical humid climates, moisture and condensation on walls lead to significant damage of buildings. The purpose of this article is to present a numerical model to improve the prediction of internal humidity in buildings. Thermal simulation codes usually evaluate moisture due only to airflow transfers. The model presented takes into account the moisture transfers between walls and air inside a zone. It allows a forecast of the quantities of liquid condensed on a surface. An experimental comparison is presented to appreciate the improvement of the model.
A preliminary investigation has been carried out to determine the potential for using ultra-wideband (UWB) radar to determine the moisture level within building envelopes. Radio waves are affected by moisture content because their reflection from the surface of a material depends upon the dielectric
This study calculates the effect of permeable hygroscopic structures on IAQ and thermalcomfort in a cold climate. Simulations are carried out for a detached house and application ofcriteria for assessment of indoor climate is given. The results show that hygroscopic structuressignificantly decreased the fluctuation of indoor relative humidity. In the winter,hygroscopicity had only minor effect on indoor climate, but in the summer, hygroscopicityhad some effect on thermal comfort, which was improved at lower ventilation rates.
During the construction of Dhoby Ghaut Station on the MRT North-East line a 10-storeycommercial development was completed. The facade is a vented cavity of a triple glazedconstruction comprising of an Insulated Glazed Unit, cavity blind with natural ventilation, anda single internal operable glazed layer. This type of facade technology has been used inEurope; however, its relevance in tropical climates where buildings are cooling-dominatedneeds to be carefully considered.
As part of a graduation project, a typical ‘sick’ office building was subject to a retrofit R&D programme. It concerned a typical 1975 building with a sealed façade and a central climate control system with induction units. An interview of the some of the
This paper presents results of an ongoing research conducted at the BEST Polytechnic ofMilan about the correlation between the over time degradation of building envelopcomponents and the indoor climate.
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