Commission and performance contracting of ventilation systems in practice. Determination, analyses and consequences for practitioners and contractors

Studies in the Netherlands show that ventilation systems of dwellings don’t comply with building regulations. The main shortcoming is insufficient ventilation. This applies to both the house as a whole as to individual rooms. Ventilation systems produce too much noise, for example due to the lack of adequate silencers, the location of the ventilation unit and the dimensions of the air ducts.  Because ventilation systems make so much noise when operating at high flow, the ventilation is often only set to the lowest speed (van Dijken, 2011). Because the houses are often not sufficiently airtight, the designed ventilation flows are not achieved especially for houses with natural supply and centralized mechanical extract ventilation. Other European countries are struggling with similar quality issues. In France, an analysis of 1,287 houses showed that 68% of single-family homes were found to be non-compliant with regard to ventilation regulations. Many of these malfunctions could be avoided through the implementation of quality management tools. These tools should be available at different stages of the construction process, and should be efficient and effective. (Jobert, 2013).  Performance contracts can be an important driver for quality management and to focus on performance rather than the placement of components. Simplified tools should make it possible during the construction process to simply and effectively measure the most important aspects affecting the overall performance of the ventilation system: noise from the ventilation system, volume flow and airtightness of the building envelope.