As LED wall packs gain market share, the most common designs for wall packs will most likely change (in fact, this is already happening). LED wall packs do not effectively use prismatic lenses like more traditional light sources. The optics of the fixture do not work the same way. Consequently, LED wall packs are more likely to be designed to use clear or frosted non-prismatic lenses.
Up to now, the most popular commercial wall packs had prismatic lenses made of either polycarbonate or heavy borosilicate glass (shown here). Those wall packs most often used metal halide, high pressure sodium, or compact fluorescent lamps and ballasts. The prismatic lens, when properly formed, provides a refractor-type effect that diffuses and distributes the light with minimal light loss. With this lens, light can be evenly distributed and directed and glare is reduced.
LED wall packs are more likely to use clear or frosted, non-prismatic lenses. When LEDs are used in wall packs with borosilicate glass, the optics of the fixtures do not work the same way. For the LEDs to be effective, they have to hit the glass at different angles. In most instances, this impedes the performance of the LEDs and the total light output. Efficacy can be lowered by modifying the placement of the LEDs to regain quality optics.
The primary reason for the photometric change is the difference in the light source. Metal halide, high pressure sodium, and compact fluorescent lamps blast light in all directions. LEDs are a pointed source. This is similar to the why a halogen filament can be directed in a PAR38, but fluorescent coils in the same lamp shell would send light everywhere.
While LED wall packs will still be made with prismatic lenses because some traditionalists prefer prismatic lenses, LED wall packs with clear and frosted lenses should be considered first. Still, you must select the appropriate fixture for your specific project. A full cutoff luminaire, for example, effectively lights the area below it and is best for limiting light trespass.
If the light is to be directed outward, an adjustable LED wall pack might be the superior choice. Featuring clear glass, the LED point source can beam spread can be controlled and the light can be directed where it is desired. When lighting objects or areas, though, it must be considered if the LED light source will shine in people’s eyes. The LEDs can be very intense when directly viewed.
Speak to an Access Fixtures Lighting Specialist about Choosing the Right Fixture
Access Fixtures offers a full line of LED wall packs to suit every application. Wall packs offered vary in size, style, color. We also offer custom finishes using RAL color codes to match existing architecture. If you have a lighting question, we will be glad to answer your questions. We want to make sure you get the exact fixture for your needs, your budget, and your goals. We are passionate about lighting and love what we do—we’ll get you an answer. To speak with an Access Fixtures lighting specialist, call (800) 468-9925.