As we breathe we absorb oxygen from the air, which goes into our blood; we release carbon dioxide (CO2). Where normal air has a CO2 concentration of only around 0.04%, used air contains a higher level of CO2. Once the concentration reaches 1%, it has a narcotic effect on the human central nervous system – and even a slight increase in airborne CO2 leads to acidification of the blood. When this happens, blood pressure drops and blood becomes less effective at binding oxygen, even though there is generally sufficient oxygen available in stuffy rooms.
Opening windows is essential to counteract this effect. The best ventilation method is intensive, short-term ventilation around every two hours, as a permanently open window causes the air to lose too much valuable moisture – especially in winter. But many offices and public facilities no longer have windows that can be opened. This makes intelligent ventilation systems crucial, and requires employers to ensure that the ventilation or air-conditioning system is set correctly. GEALAN resolves the problem – both actively and passively.