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:
“The human condition is such that pain and effort are not just symptoms which can be removed without changing life itself; they are the modes in which life itself, together with the necessity to which it is bound, makes itself felt. For mortals, the “easy life of the gods” would be a lifeless life.”
—Hannah Arendt (1906–1975)
“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)
“Mr. Speaker, at a time when the nation is again confronted with necessity for calling its young men into service in the interests of National Security, I cannot see the wisdom of denying our young women the opportunity to serve their country.”
—Lyndon Baines Johnson (1908–1973)