Ventilation for housing

The physical indoor climate in housing is affected by many factors e.g. design, choice of materials and the possibility for airing. However, the indoor climate is also dependent on how the building is used and where ventilation plays an important role regards decontamination of materials, bio influences, high humidity, dust mites and not least excess temperatures.

In step with buildings becoming more air tight, ventilation has become even more important for the indoor climate. Today, new builds are so air tight that a mechanical ventilation system is almost indispensable. On busy days one can easily forget to let some fresh air in or visa versa forget to close the windows again after airing. Many activities take place in a building which develop bio influences and damp from water. Damp from water results in an increase in the humidity and if this occurs over a longer period of time then this can give rise to bacteria, mildew and dust mites.
Dust mites are not an actual problem but they can constitute a risk for people who suffer with allergies. Dust mites can be found in all homes from a few to several thousand in a gram of dust. The number of dust mites can be reduced to a minimum with sufficient ventilation of the building during the winter, where the relative humidity is ≤ 45 % for at least one consecutive month a year.

Strong sunshine through windows and the use of electronic equipment can result in high room temperatures in well insulated buildings. The heat can be limited by using sun blinds and reducing the use of electronic equipment to a minimum. The heat can also be reduced by airing or by mechanical ventilation.