Where does ventilation collide?

In physical oceanography, ventilation is the process by which subsurface water acquires its properties at the sea surface and is then carried into the interior, so that deeper layers are periodically renewed and resupplied with dissolved gases rather than stagnating. Luyten, Pedlosky, and Stommel's 1983 The ventilated thermocline showed how water subducted beneath the wind-driven subtropical gyres sets the temperature, salinity, and oxygen of the thermocline from above. The referent is the renewal of interior ocean water by exchange with the surface, tracked through transient tracers and dissolved oxygen, and it has nothing in common with a lung drawing breath or an air handler flushing a room beyond the shared idea of refreshing a body of fluid.[1]

Unit

The rate and age at which interior water was last in contact with the surface

Recovery means

Not applicable

Measured by

Inferred from transient tracers (CFCs, tritium), apparent oxygen utilisation, and water-mass age along subduction pathways

In building services engineering, ventilation is the controlled supply of outdoor air to, and removal of stale air from, an indoor space to dilute occupant-generated pollutants, odours, moisture, and carbon dioxide and maintain acceptable air quality. Awbi's Ventilation of buildings treats the airflow, air-change rates, and distribution strategies (natural, mechanical, or mixed) that decide whether a room is adequately served. The referent is an engineered air-exchange rate for a built space, measured in air changes per hour or litres per second per person, and it is a wholly separate thing from ocean renewal or breathing, sharing only the word's meaning of letting fresh in and stale out.[2]

Unit

The outdoor-air supply rate to a space, in air changes per hour or L/s per person

Recovery means

Not applicable

Measured by

Quantified by air-change rate from tracer-gas decay, CO2 concentration, or measured supply airflow against design standards

In respiratory physiology, ventilation is the bulk movement of air into and out of the lungs with each breath, with minute ventilation the product of tidal volume and breathing frequency and alveolar ventilation the fraction of that air that actually reaches gas-exchanging alveoli rather than dead space. West's Respiratory physiology: The essentials sets out how ventilation must be matched to pulmonary blood flow for efficient gas exchange. The referent is the volume of air breathed per unit time by a living organism, measured in litres per minute, and it is distinct from the renewal of interior seawater or the air-change rate of a building, joined to them only through the common notion of refreshing air.[3]

Unit

The volume of air breathed per minute (minute or alveolar ventilation), in L/min

Recovery means

Not applicable

Measured by

Measured by spirometry and capnography as tidal volume times respiratory rate, with alveolar ventilation corrected for dead space