An article by the medical journalist Werner Stingl
People may survive without food for several weeks, without water for a few days but only for a few minutes without air. An uninterrupted supply of air with its 21% oxygen, 78% nitrogen and the small remainder of carbon dioxide, noble and other gases is the most essential thing we need to survive. Adults will pump more than 10,000 litres of air through their lungs in a 24-hour period. Day and night, all their lives.
People these days get most of their air indoors in contrast to people who lived just a few generations ago. Indoor climates are thus becoming increasingly important to health and well-being. But it still often leaves a lot to be desired.
The quality of the air outside is usually even better in major cities where the air is full of emissions than inside the buildings. That is because critical values are easily reached in enclosed spaces while – in the relative infinity of the windy outdoors – stale air and airborne pollutants from natural and artificial sources usually become quickly diluted to concentrations that are harmless. The situation is exacerbated by window and door designs that in the interest of saving energy have been modified to become more airtight and so prevent the spontaneous exchange of air.
Furniture, floor coverings, wall paints and cleaning agents give off gases that are potentially harmful to health. Some soil minerals and building materials may release radioactive radon, which accumulates in stagnant room air. Cooking, washing, clothes drying and water vapour given off from the lungs and skin threaten to transform living spaces into wetlands where moulds thrive and contaminate the breathing air with their spores.
Regular airing prevents such problems and is indispensable to a healthy indoor climate. But we all too often simply don't remember to let fresh air in, keep the windows closed and the fresh air out. In a stuffy atmosphere, we may feel an indistinct uneasiness, can’t concentrate as well and sleep more restlessly at night But we are unable to draw on clear sensations that – like the feeling of pain – provide unmistakable and timely warnings that the quality of the air inside is gradually deteriorating.
Computer-aided, high-quality room ventilation systems represent a contemporary alternative or supplement to the tried-and-tested intermittent airing. They automatically create optimum room climates where the air is continuously replaced with the help of regulating humidity sensors, filters and heat-recovery systems. And they do all that without the necessity of allowing heat to escape out of the window.