Necessity
When people or animals are present in buildings, ventilation air is necessary to dilute odors and limit the concentration of carbon dioxide and airborne pollutants such as dust, smoke and volatile organic compounds (VOCs). Ventilation air is often delivered to spaces by mechanical systems which may also heat, cool, humidify and dehumidify the space. Air movement into buildings can occur due to uncontrolled infiltration of outside air through the building fabric (see stack effect) or the use of deliberate natural ventilation strategies. Advanced air filtration and treatment processes such as scrubbing, can provide ventilation air by cleaning and recirculating a proportion of the air inside a building.
Read more about this topic: Ventilation (architecture)
Famous quotes containing the word necessity:
“Then did they strive with emulation who should repeat most wise maxims importing the necessity of suspicion in the choice of our friends—such as “mistrust is the mother of security,” with many more to the same effect.... But notwithstanding the esteem which they professed for suspicion, yet did they think proper to veil it under the name of caution.”
—Sarah Fielding (1710–1768)
“Were it not for the corruption and viciousness of degenerate men, there would be no ... necessity that men should separate from this great and natural community, and by positive agreements combine into smaller and divided associations.”
—John Locke (1632–1704)
“It is necessary to posit something which is necessary of itself, and has no cause of its necessity outside of itself but is the cause of necessity in other things. And all people call this thing ‘God.’”
—Thomas Aquinas (c. 1225–1274)