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1945 Theatre Catalog, 4th Edition, Page 517 (491)

1945 Theatre Catalog, 4th Edition
1945 Theatre Catalog
1945 Theatre Catalog, 4th Edition, Page 517
Page 517

1945 Theatre Catalog, 4th Edition, Page 517

Air Disinfection for Theatre Auditoriums

Post-War Application of Hygeaire System Termed Practical Air-Sanitizing Method

Another notable advance in the rapidly expanding science of air sanitation is the adaptation of the Hygeaire system for the radiant disinfection of air in the theatre auditorium. This new development represents the first post-war application of the Hygeaire ultraviolet germicidal unit (manufactured by the American Sterilizer Company) for the improvement in environmental sanitation and for the practical control of airborne infection in the public health field.

Ever since the commercial development some four years ago of the hotcathode ultraviolet germicidal lamp, there has been a keen interest and a highly competitive effort among fixture manufacturers in an attempt to devise a practical means for the installation of the ultraviolet lamp within the theatre auditorium. During the war years, a premium on engineering time and skill prevented a careful study of the various factors involved in such installations, although some very definite contributions were made by certain scientific investigators in air-pollution surveys of both air-conditioned and noneair-conditioned theatres. As the result of insufiicient technical data and information, progress in this field has been rather limited and in recent months additional complications have developed, due to a diversity of opinion as to the most efficient method for the disinfection of air Within the theatre auditorium.

FIGURE I.-De:ontaminatian and disinfection ettectiveness of air changes and From an inspection of the curves, it would appear that from 60 to 120 air changes an hour would have to be maintained in order to have, of itself, any value in the prevention of the spread

air-change equivalents (lethes) an hour are shown.


Issoriate Director of Research. American Sterilizer Company

It is the duty of every theatre owner, manager, or operator to familiarize himself with the present concept of sanitary ventilation, its meaning, purpose and ultimate effects upon the health and wellbeing of his patrons. Two schools of thought, and two entirely different methods of approach to the problem of disinfecting the air within the theatre, are being promoted at the present time. Both of these methods are fairly simple in principle and each has 'its recognized advantages and disadvantages, even though the end result in either case is the destruction of air-borne bacteria, thereby assisting in the control of airborne infections in enclosed spaces.

The first and possibly the most widely .

publicized of these two methods applicable to the theatre field is the installation of ultraviolet germicidal lamps directly within the air-conditioning system, sometimes referred to as a duct installation. In contrast to the duct type of installation is the method of direct irradiation of the air in the upper areas of the room in which the effects of sanitary ventilation are to be secured. This method is now recognized to be a simple and efficient method for the germicidal treatment of air.


When individual and adequate supplies of air can be furnished to each person, the problem of air-borne infections disappears. However, it is almost impossible to arrive at such an ideal under general living conditions, and it now becomes necessary for the purpose of this discussion to determine just how much can be done by ventilating procedures to limit the spread of air-borne infection. Almost everyone now recognizes that in sneezing, coughing, spitting, breathing, and speaking, bacteria and viruses are projected into space. These agents are disseminated in droplets of diverse sizes. Droplets larger than 0.1 millimeter in diameter will respond more rapidly to gravitational force and will settle out a short distance from their point of origin. Eventually such droplets will dry and become part of the dust. The future of the organisms they contain will depend on the steps taken to render this dust harmless. The behavior of dr0p1ets of smaller size is somewhat diii'erent and the buoyancy of the atmosphere helps to maintain them in a state of suspension for long intervals, and air currents may transport them for long distances. When these smaller droplets of less than 0.1 millimeter in diameter evaporate they leave behind a residue of fine dust like particles in which disease producing germs may be incorporated.

of respiratory diseases by air-borne bacteria and viruses. Air conditioning systems of such capacities are hardly feasible either in economy of operation or efficiency or performance. (Permission to use this chart has been granted by Dr. L. J. Buttolph, of the General Electric Company's Lamp Department, Neia Park, Cleveland).

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1945 Theatre Catalog, 4th Edition, Page 517