FreeAir
Free air refers to air that is not confined, enclosed, or pressurized by a container, duct, or other enclosure. In practical terms, it is ambient atmospheric air at or near standard atmospheric pressure, found in open environments rather than inside sealed systems. Its composition is those of Earth’s atmosphere, primarily nitrogen and oxygen, with variable amounts of water vapor, carbon dioxide, and other trace gases depending on location and conditions. Temperature and humidity of free air can change with weather, time of day, and altitude.
In engineering and building design, free air is contrasted with air that must be moved or contained
In acoustics and measurement, free air or free-field conditions denote an environment where sound propagates with
Other uses include meteorological discussions of unconfined air masses and general references to air in its