Music
Sounds systems can be located in the plenum above open louver designs or in a service or perimeter area.

Fire Ratings
Luminous elements are available to meet all types of fire rating requirements. All metal louver designs will not support combustion. Vinyl louvers, and vaulted shapes, as well as our new type F.R. flat sheet are classified as self-extinguishing. Acrylic and polystyrene lenses, flat diffusers, drop dish, vaulted shapes, and louvers are classified as slow burning. Local code requirements should be checked to determine exact approval for various classifications of building areas and materials.

Fire Protection Systems
In most areas, sprinkler systems can be located above open louvers or solid formed vinyl diffusers. On other luminous designs, they can be located in a service or perimeter panel.

Weight
Luminous ceiling systems are furnished with the hanger design and spacing appropriate for weight of the design. The approximate weights are: Quad designs 2.5 lbs., aluminum and plastic louvers 0.80 lb., flats lens 0.4 lb., vinyl 0.2 lb. (all per square foot.)

Uniform Brightness
Lighting design can be the most important element in a luminous ceiling. Creating the proper number of comfortable footcandles is not usually the problem but rather avoiding a distortion in the appearance of the ceiling. The lighting of a luminous ceiling must be uniform to assure its beautiful appearance.

• Light sources should be continuous and the spacing symmetrical.
• Our spacing ratio chart suggests the proper relationship between plenum depth vs. fixture spacing.

A non-modular design loses its monolithic effect to bright streaks. Modular elements lose their balance with non-symmetrical lighting. A luminous ceiling must retain a comfortable evenly lighted surface and proper lighting design will assure this.

Varying Light Levels
More than one light level can be achieved simply and inexpensively by switching alternate rows of lamps. Even greater flexibility can be provided by having every third lamp on one switch and the balance on a separate switch. An application designed for 120 f.c. can achieve light levels of 40 f.c., 80 f.c. and 120 f.c. simply by adding one standard switch. It is important that the spacing ratio on the lowest level provide even lighting.

Fixture Layout
The fixtures should be in continuous rows and be run wall to wall. The space from the end of the rows to the wall should not exceed 12" on normal plenums and 6" on shallow plenums. The spacing between rows should be uniform and the space between the last row and the wall should be approximately 1/2 of the spacing between rows.

Recommended Light Source
For most applications, our standard single lamp, open tube strip fixture is the proper choice. This unit allows the light to be spread most evenly and is usually the most efficient and economical.

Fixture Reflectors
Where plenum conditions are not favorable to good light reflection, we recommend fixtures with reflectors be used to direct the light downward.

Highlighting
Luminous ceilings can be used to focus attention on and highlight important areas. Rather that an overall ceiling, luminous islands emphasize specific key areas.

Lighting for Formed Luminous Elements
In lighting vaulted plastic elements, it is important that the lighting be symmetrical to the shape. This eliminates shadows which detract from the beauty of the shape.

Lighting Requirement
When calculating the light level from our C.U. charts, it is crucial that the luminous area comes to 85 - 90% of the room area. When a smaller luminous area is used, 60 - 85% of the room, it must produce enough light for the entire room area. In addition to this factor, an additional 10 - 15% more lumens should be added to counter the effect of moving the wall surface back from the light source.