Öndunarloft

Öndunarloft is the gas mixture that makes respiration possible for humans. The concept concerns both the total atmospheric pressure and the proportion of oxygen, together with the presence and concentration of other gases and moisture that affect breathing comfort and safety. In everyday environments, öndunarloft is the ambient air we breathe.

Composition on Earth. Dry atmospheric air at sea level consists roughly of 78% nitrogen and 21% oxygen, with trace amounts of argon, neon, carbon dioxide and other gases. Humidity and temperature influence how the air feels and how readily oxygen is absorbed by the lungs. The partial pressure of oxygen in the breathing air determines how well tissues receive oxygen; at higher altitudes, lower ambient pressure reduces this partial pressure and can lead to hypoxia if the air is not adjusted.

Safety and quality. Safe breathing depends on maintaining a balanced gas mixture and controlling contaminants. In indoor environments, air quality guidelines emphasize adequate ventilation, low levels of pollutants, and a reasonable carbon dioxide concentration, often around 1000 parts per million or less, to avoid discomfort and reduced cognitive function. Oxygen concentration is typically kept near natural levels (roughly 19.5–23.5% in many closed habitats) to support metabolic needs.

Specialized contexts. Some environments require engineered breathing mixtures. Scuba diving uses air or enriched oxygen mixtures to manage nitrogen narcosis and oxygen exposure at depth. Submarines and spacecraft use carefully controlled air supplies with scrubbers for carbon dioxide and filtration for contaminants, ensuring a stable öndunarloft for crewmembers over extended periods.

See also. Air quality, ventilation, breathing mixtures, diving gas mixtures.