To get some fresh outdoor air into your home is important for your health
Fresh outdoor air contains 400 ppmv (parts per million volume) of CO2 (carbon dioxide). Humans and animals exhale the same gas at the same time in amount that depends on their physical activity. In rooms that are not sufficiently ventilated, this gas accumulates and causes what we can call the stuffy air. Staying in such rooms can lead to many health problems - from fatigue and drowsiness to irreversible damage of your health. Content of the CO2 for feeling of the fresh air is up to 700 ppmv. Values above 1000 ppmv are less suitable for permanent residence and sleeping (eg in the apartment), above 1500 ppmv is unsuitable. At 5,000 ppmv (PEL - Permissible Exposure Limit), the stay must be limited for the shortest time as possible. At 25,000 ppmv (NPK - maximum admissible concentration) there is a risk of death by suffocation. The correct ventilation intensity in the room or house can be calculated according to the number of people in the room and their physical activ...