Abstract
IT is well known that the windows of houses exposed to the sun's rays act like heat traps. They permit most of the radiant energy from the sun to pass into the building but block the low temperature radiation from inside surfaces passing out. Science Service has issued a report of results obtained by research physicists of the American Society of Heating and Ventilating Engineers in their laboratories. Formerly it was thought that glass absorbed only about ten per cent of radiation at low temperatures. The experiments show that a temperature of 550° F. must be reached before any appreciable amount of the radiation passes through plate glass. Even at 1,000° F., only a small amount passes through. Glass obviously acts as a very efficient heat trap and this has to be taken into account by the ventilating engineer. In many modern buildings, a side built almost entirely of glass is exposed to the sun's maximum radiation. On a hot summer day, the glass permits the heat from the sun to enter and practically none of it escapes. Indoors, therefore, it becomes unbearably hot. The cost of keeping a building of this nature cool is practically prohibitive. Awnings which deflect the light and are hung outside the windows are perhaps the most efficient. Shades and blinds are of little value as the heat passes through the glass, heats the blind and is convected upwards, thus heating the room. Tests proved that there is no practical difference in efficiency between clear and coloured glass.
Article PDF
Rights and permissions
About this article
Cite this article
Glass Windows and Ventilation Engineering. Nature 132, 963 (1933). https://doi.org/10.1038/132963a0
Issue Date:
DOI: https://doi.org/10.1038/132963a0