BD2011

To describe the quality of adhesive joints and connections for airtight layers, our research includes comprehensive investigations into the effect of different working conditions and accelerated aging.

Today, labels introduced in some countries to certify standardised low energy buildings, such as ‘Passive House’ in Germany and ‘Minenergie’ in Switzerland, are becoming increasingly applied in Europe.  Both labels explicitly require a threshold level of airtightness (0.6 air changes per hour (ACH) at 50 Pa). For timber frame passive houses in Belgium, this requirement is commonly achieved by sealing all the joints in the interior structural sheathing, mostly consisting of Oriented Strand Boards (OSB).

The air tightness of building has been a serious problem over the last 30 years. In 1979 the international Air Infiltration Centre (AIC) was erected within the International Energy Agency (IEA) platform. Infiltration of cold air into buildings needs to be heated to reach to a comfortable indoor climate. But the energy penalty due to that should be minimized. The AIC (later AIVC) had as one of their tasks to find solutions for good air tight buildings and to promote the knowledge about building construction to reach acceptable level of air tightness of buildings.

We have developed a simple model to estimate ductwork leakage and heat conduction losses in steady-state conditions for a balanced ventilation system. Implemented in a spreadsheet, it allows us to calculate their impact on heat recovery efficiency consistently with EN 15241 without the need for a dynamic simulation tool. One case study shows that the global heat recovery of a balanced ventilation system with a nominal heat recovery of 80% can be reduced to less than 50% if the ductwork leakage and thermal resistance are poor.