Core element of the DIN 1946-6: Distinction of four ventilation levels
1. Ventilation for moisture proofing
This ventilation level is to ensure adequate ventilation of the building as a function of the respective thermal insulation level. The aim is to avoid damage to the building caused by moisture, also during temporary absence of the residents and reduced moisture loads. This ventilation has to be ensured at all times and is user-independent.
2. Reduced ventilation
This ventilation level is also practically user-independent. In this case, the minimum hygienic standard and protection of the building is to be ensured during short-term absence of the residents (daily work etc.).
3. Nominal ventilation
Under normal use conditions the nominal ventilation describes the minimum air exchange rate required for maintaining hygienic and health standards as well as for the protection of the building. Nominal ventilation can, in some cases, include the residents’ proactive participation in window ventilation measures.
4. Intense ventilation
Intense ventilation is aimed to remove peak loads caused by cooking, washing etc. The resident can also be proactively engaged in this ventilation level by opening windows.
The level of insulation and the location of the building are also included in the calculation basics for the ventilation levels acc. DIN 1946-6. In this way, any leaks in the building envelope are detected, expected loads based on the usable floor space are taken into account and the natural air infiltration is estimated using the wind load.
If, according to the ventilation concept, the natural air supply is seen as being inadequate for a ventilation that will ensure protection against moisture, the responsible designers have to provide additional ventilation measures.
In addition, the new DIN 1946-6 provides the designer with legal certainty in decisive issues. Some issues, however, have still been omitted. For example, it is not possible to define the amount of active window ventilation that can be expected from a resident who works fulltime. It is also a problem accounting for different overall weather conditions, such as mild winters or spring and autumn as transitional seasons. This is because in some weather conditions, or under severe temperature fluctuations, a complete air exchange may be necessary several times a day.