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Use of Plexiglas acrylic sheet for Lighting Applications

Lighting Diffusers Using Fluorescent Lamps - Lighting can be built into ceilings and overhangs by installing panels of white translucent Plexiglas below fluorescent lamps, as shown below. The Plexiglas panels rest on the projecting edges of the wood moldings or metal framing. If diffuser is outdoors, cut material 1/4" smaller than the opening to allow for thermal expansion of the material. For service access to the lighting, the diffusing panels are pushed up, tilted and removed. Plexiglas in 1/4" thickness is recommended for installations with areas larger than two square feet. For uniform diffusion of light, the distance from the Plexiglas to the fluorescent lamps should not be less than two-thirds of the distance between rows of lamps. All surfaces above the diffusing panels should be given at least two coats of high-reflectance white paint, with white enamel as a finish coat.

Lighting Diffusers Using Incandescent Light Bulbs - When using Plexiglas in an incandescent lamp, you must provide sufficient space for ventilation between the light bulb and Plexiglas to prevent overheating and softening of the Plexiglas. For best results - even illumination and no hot spots - use show-case bulbs. The formula for determining the minimum distance between a given wattage bulb and Plexiglas:

Minimum Distance, Bulb to Plexiglas = 1/2 the square root of the bulb's wattage.

Note: The minimum distance can be reduced by providing ventilation for heat to escape, however there is no general formula to determine the reduction.

A general rule of thumb for indoor applications of Plexiglas lighting white is to use:

Thickness Unsupported Horizontal Span

1/8" 0" - 24"

3/16" 24" - 36"

1/4" 36" - 48"

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