TESTING A METHOD FOR THE EVALUATION OFTHE AIRTIGHTNESS OF VENTILATION SYSTEMSIN EXISTING BUILDINGS

摘要

The airtightness of ventilation ductwork is an important element of the global performance of ventilationsystems. Nevertheless, it is too often neglected in practice.Today, the new French Thermal Regulation (RT2000) encourages taking it into account as the energy lossescalculation includes an additional part which is directly related to the additional air flow through ductworkleakages.If we want to improve the results and the practice, we have to take into consideration the whole ventilationinstallation : the ducts and accessories, of course, but also the connections between ducts and air terminaldevices, the connections between ducts and fan units, the characteristics of these fans, CTA, etc. We also have totake into account the reality of the building site.This paper shows how to implement a methodology for measuring, on site, the global airtightness of ventilationinstallations. It is based on real applications on commercial and residential buildings, in France. It shows thefeasibility of the method and, notably, the difficulties which were encountered for the investigations inmulti-family buildings.Measurements results are given and compared to the standard classes. They show the poor quality of airtightnesson the most of installations which were tested. These results are in agreement with previous studies.In parallel, this work enables to identify some of the causes of the low airtightness of ventilation systems.