Symposium on Illumination

Abstract

Abstract The first paper of this symposium outlines a method by which the amount and distribution of daylight illumination that should be produced by any specific window arrangement in the interior of a building may be predicted. The method is based upon rigorous theoretical analysis and has been checked repeatedly by field tests upon full-size buildings as well as by laboratory tests upon models of buildings. Some results of the application of the method to analysis of the lighting effect of changes in the fenestration of typical buildings are discussed. A bibliography and a brief digest of the most significant literature known to the authors include important data on the effects of window glass, shades and blinds, mullions and columns, light-reflecting surfaces both within and without the building, sawtooth, monitor, and other types of roof in single-story buildings, and light courts in multistory buildings. Ward Harrison, in the second paper, points out that since daylight provides adequate illumination for only about one-half of the working area in a modern multi-story factory building, artificial illumination is essential for effective use of the entire space for productive purposes. The procedure for the correct design of such systems is outlined in the paper. The last paper, by Munroe and Cook, considers light as an important factor in the successful operation of any industrial plant. Inadequate lighting, i.e., lighting of a low intensity with glare present and the illumination improperly distributed throughout the interior, will hinder the various industrial processes, while adequate lighting, i.e., sufficient intensity, glare eliminated, and a satisfactory distribution of light, will assist in the operation of industrial plants. Adequate lighting will increase production, the average increase being 15 per cent at a 2 per cent cost of the payroll; it will decrease industrial accidents, this reduction producing a saving in plant operation costs; it will reduce labor turnover and spoilage, again assisting in the production of materials at a low cost; and it will assist in the maintenance of the health of the employees, which tends to produce a greater organization efficiency. These factors, with their combined influences, make it highly desirable that the lighting of a plant receive consideration similar to that of the machinery to be installed, because it can be stated without question that the efficient operation of an industrial plant is influenced to a certain extent by the character of the illumination used.