Jasper County Democrat, Volume 2, Number 41, Rensselaer, Jasper County, 13 January 1900 — Proper Ventilation, [ARTICLE]

Proper Ventilation,

The method of natural ventilation that is. providing an opening in or near the ceiling for the outlet of foul air—is both common and sensible. Referring to this method, a writer in The Building World says that the efficiency of the plan is proved scientifically, and is based upon the simple fact that heat expands and cold contracts, a natural law to which air is no exception. Foul air is generally warmed to some extent, and then rises to and passes out by the opening at the higher level, its place being taken by cooler air entering at the lower of the two openings—in order to insure ventilation two openings at least being necessary, one to act as an inlet and the other as an outlet The effectiveness of this natural ventilation depends entirely of course on the difference of temperature between the external air and the internal, and, this being the case, the system may be very effective in winter and utterly fail in snmer; and, as air dilates or expands 1-491 of its volume for each degree of Fahrenheit that its temperature is raised, its weight is consequently reduced in the same proportion, and tne lighter air is thus forced to the upper part of the room by the greater weight of tlie cooler air.