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:
“I want the necessity of supplying my own wants. All this costly culture of yours is not necessary. Greatness does not need it. Yonder peasant, who sits neglected, carries a whole revolution of man and nature in his head, which shall be a sacred history to some future ages.”
—Ralph Waldo Emerson (1803–1882)
“The necessity of poetry has to be stated over and over, but only to those who have reason to fear its power, or those who still believe that language is “only words” and that an old language is good enough for our descriptions of the world we are trying to transform.”
—Adrienne Rich (b. 1929)
“Undoubtedly if we were to reform this outward life truly and thoroughly, we should find no duty of the inner omitted. It would be employment for our whole nature.... But a moral reform must take place first, and then the necessity of the other will be superseded, and we shall sail and plow by its force alone.”
—Henry David Thoreau (1817–1862)