The preconceived notion that one should ventilate because buildings have become too airtight is not correct. The opposite is true: For good ventilation, excellent air-tightness is essential.
By ventilation, ‘fresh’ outside air supplied and ‘used’ air is vented outdoors. Ventilation contributes to a healthy indoor environment for home users. In case of insufficient ventilation, moisture is accumulated in the house as well as bothersome or even harmful substances. Residents produce these substances partially themselves by exhalation of moisture and waste substances (such as carbon dioxide) and for example by smoking, showering and cooking. In addition, substances are also released from the house itself, for example from flooring/carpets or building materials. When ‘used’ air and moisture is not removed, an unpleasant and unhealthy indoor environment can be the result. Contaminated indoor air is perceived as stuffy and can lead to odour hindrance. Because of this, fatigue, headaches and complaints about irritated eyes and respiratory system can occur. Especially for people with respiratory disease, good ventilation is essential.
Takes place through wall grids, windows and / or air supply and exhaust channels. Air supply and removal can take place both naturally (by wind pressure) as well as mechanically (by means of a fan). Well into the twentieth century, mainly natural ventilation was used. Nowadays almost all mechanical systems are used, making ventilation less dependent on the weather. Furthermore, ventilation can occur (unintentionally) by infiltration: air flows through for instance cracks and crevices in the building construction. In modern homes, the amount of infiltration is limited because of energy saving measures. Irrespective of the nature of the ventilation system, windows that can be opened are always necessary for the outlet of air (airing).
Domestic ventilation systems
Four types of ventilation systems can be distinguished (NPR 1088):
- natural supply and natural removal (system A);
- mechanical supply and natural removal (system B);
- natural supply and mechanical removal (system C);
- mechanical supply and removal (also known as balanced ventilation), with or without heat recovery (WTW) (system D).
Our measurements only focus on the systems with natural supply and mechanical removal (system C), and balanced entilation, or mechanical supply and removal (system D). The first two ventilation systems (systems A and B) hardly exist in new homes in The Netherlands. The researched ventilation systems are described further below.
See buttons for explanation of ventilation C and D. go to knowledge.