Netherlands

The building airtightness is essential to achieve a high energy performance. In most countries however, it is not mandatory to measure the airtightness. In the Netherlands it is common practice to just take a couple samples in a housing project. These samples do not give a good indication for all the buildings in a project. It is therefore important to measure the airtightness of all the buildings.

Ventilative cooling can be used as a passive cooling measure to reduce the cooling energy demand of buildings. It can be used during the day, directly removing excessive heat gains, or during the night (i.e. night flush), in which cold outdoor air flows through the building and cools down the indoor air volume and subsequently the thermal mass of the building. Night flushing reduces the indoor air temperatures at the beginning of the next day and the cooling demand over the day.

The indoor air quality is very important for the well-being of occupants, especially in the case of young babies. This research focuses on the air quality of the surrounding air inside a crib with sleeping infants. To study the effects of different sleeping positions of the baby with in the crib a measurement setup was created in the laboratory. The breathing of an infant was simulated by means of a baby doll with air supply mixed with CO2 and measured at different sensor locations for different sleeping positions.

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).

The last decades big steps have been made on the road to develop and design energy neutral buildings. Despite the large list of developments and improvements of all kind of energy saving technologies we see specifically for the larger non-residential buildings that the electric energy use for fans hardly show any reduction and becomes a dominant factor in the total energy use of these buildings. The fan energy currently counts already for approximately 15-20% of the total building related energy and becomes increasingly important. 

Various studies show a deterioration in indoor air quality after renovation and energy saving measures. NZEB dwellings are at the moment at an airtightness level, that the old slogan make buildings airtight and ventilate right is an very import solution for a good IAQ, but not without source control.