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:
“If necessity is the mother of invention, then resourcefulness is the father.”
—Beulah Louise Henry, U.S. inventor. As quoted in Feminine Ingenuity, ch. 13, by Anne L. MacDonald (1992)
“With my desire to write he seemed in full sympathy, and in urging our early marriage he argued that my first necessity was leisure in which to develop and to master my craft. It appeared to me that with such a man as teacher and guide I could not fail, and it was in a queer mixture of young love and vaulting ambition that I became a wife.”
—Rheta Childe Dorr (1866–1948)
“We need not have the loftiest mind to understand that here is no lasting and real satisfaction, that our pleasures are only vanity, that our evils are infinite, and, lastly, that death, which threatens us every moment, must infallibly place us within a few years under the dreadful necessity of being forever either annihilated or unhappy.”
—Blaise Pascal (1623–1662)