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:
“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)
“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)
“We are sure that, though we know not how, necessity does comport with liberty, the individual with the world, my polarity with the spirit of the times. The riddle of the age has for each a private solution.”
—Ralph Waldo Emerson (1803–1882)