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1945 Theatre Catalog, 4th Edition, Page 519 (493)

1945 Theatre Catalog, 4th Edition
1945 Theatre Catalog
1945 Theatre Catalog, 4th Edition, Page 519
Page 519

1945 Theatre Catalog, 4th Edition, Page 519

TABLE 1-Specifications and Ratings of the Hygeaire assemblies, Model HUVM' . 30 and Model HUVM-15.

Model Model HUVM-30 HUVM-15

Input of germicidal tube and ballast ,,,, ., 40 watts 20 watts Germicidal UV energy output ........................ ., 7.2 watts 2.9 watts

Bacteria (at one foot from tubers-time to effect 99 per

cent kill

4-5 seconds 10-12 seconds

Mold (at -0ne Entrants;liaise. $59553..."

cent kill ......................................................................... .,

............................... .. 4-5 minutes 10-12 minutes

Maximum intensity-(microwatts to the square centi meter at one meter) Length Width . Height .... ..

Circuit voltage, a.c. ....................................................... ..

80 32

36 inches 18 inches 6 inches 6 inches 9 inches 9 inches

.............................. .. 110-125 110-125


Any equipment (fixtures) designed for use with bactericidal lamps must conform to certain basic fundamentals. Those considered to be of prime importance are ( 1) adequacy of design to insure safety of occupants of the irradiated space from excessive direct or refiected energy, (2) shape of reflector to allow the maximum possible of 2537Angstrom energy to reach the surrounding air without reflection, and it should reflect the remaining energy, preferably once only, in such a direction as to insure a maximum possible travel through air before absorption by the surrounding ceiling and the side walls. For the usual ceiling height, this means a design to direct all the germicidal energy from the tube in as nearly a horizontal direction as possible. In addition, safety and over-all efficiency as well as convenience and good appearance are desirable adjuncts in design.

The complete Hygeaire assembly illustrated in Figure 2 consists of a specially designed refiector, reflector housing, bactericidal lamp, baffle, conductor-cord and plug. Specifications and ratings of available models are given in Table 1.

The fixed baffle is one of the special features of Hygeaire. It serves to protect the eyes and skin of occupants in the irradiated space against a possible conjunctivitis or erythema by confining the direct beam to the room area above the line of vision.

The reflector housing is designed to insure a permanent contour on the reflector, to provide a mounting for the baffle and to permit exposed surface or recessed mounting. Stock reflector housings are available in white or cream white.

The Hygeaire requires no fan or forced circulation for effective operation. Thermal air currents, due to window and door seepage and wall and radiator temperatures are sufficient to convey bacteria and infected droplets to within the disinfecting field.

Figure 3 illustrates a specially designed Hygeaire fixture for side wall mounting within the theatre auditorium. The over-all dimensions and characteristics of this special type unit are essentially the same as for the standard Hygeaire fixture shown in figure 2, except that a series of vertical louvres are incorporated in the front of each unit to guard against exposure to the direct radiation at close range. In addition, this louvre principle overcomes the objection of excessive illumination and the dis l945-THEATRE CATALOG

tractive effects of the illuminated refiector.


The air-disinfecting effectiveness of a bare germicidal lamp mounted on the side wall of a room is seriously limited by the fact that about one-half its output of 2537-Angstrom energy is absorbed by the side wall, also a large percentage of the remaining energy is absorbed in the nearby ceiling before this energy has traveled through and disinfected much of the air. Therefore, in appraising the qualities of fixtures designed for the radiant disinfection of air, one must keep in mind that ffperformance," or over-all efficiency of the unit to direct the energy in the proper direction is of prime importance.

The American Sterilizer Company has satisfied this requirement by designing a specially shaped redector (comprising a part of U. S. Patents 2,350,664 and 2,350,665), which redirects the otherwise quickly absorbed energy in a direction of maximum ray length 5 to 15 degrees

above the plane of the lamp. This feature increases by 4 to 5 times the intensity of the output from the bactericidal lamp in the most effective direction. The beam of ultraviolet radiation has considerable length but comparatively little vertical spread and consequently the reflector contour prevents little reflecting radiation in the direction below the horizontal. Such stray rays are prevented by intercepting the direct radiation of the tube in a direction below the horizontal by means of the fixed baffle described above.

A typical installation of the Hygeaire system within a theatre auditorium is illustrated in Figure 4. Here it will be observed that six Hygeaire units are required for efficient air disinfection within this space with dimensions of approximately 50 x 100 feet and a ceiling height of 25 feet. The elliptical curves in front of each unit demonstrate the distribution of the ultraviolet energy in watts to the square foot. At the present time, there seems to be agreement among scientific investigators that an intensity of 0.01 watt of 2537-Angstrom energy, uniformly distributed over a square foot area covered with bacteria, or throughout a cubic foot of infected air, will kill 63.2 per cent of the bacteria in one minute; plus 63.2 per cent of the remaining 36.8 per cent (or 86.5 per cent) in two minutes; 95 per cent in

> three minutes; over 99 per cent in five

minutes; 99.9 per cent in seven minutes, and 99.99 per cent in 9 to 10 minutes. Trial installations have shown that it is necessary to mount Hygeaire units on the side walls of the auditorium at a height of approximately 16 feet above the floor. If the fixtures are mounted at a lower level it may be found that the illumination will seriously interfere with good vision to the screen.

FIGURE 3.-An ariisf's sketch is presented of a specially designed Hygeaire fixture for sidevwall mounfing within the theatre auditorium. The over-all dimensions and characteristics of this special type unit are essentially the same as for lhe standard Hygeaire fixture shown in Figure 2, except that a series of vertical Iouvers are incorporaied in the from of each unit to guard against excessive illumination and exposure to the direct radiation.

1945 Theatre Catalog, 4th Edition, Page 519