Not all colours are equally bright. Green letters, for example, may need more LEDs installed to achieve the desired effect.
Halo-lit sign letters most commonly use white LED lighting, but other colours are also feasible. A variety of halo effects can be achieved, based on the number of LEDs and the standoff distance from the wall. A typical halo-lit letter projects about 38 mm (1.5 in.) off the wall.
The inside of the can should be painted white, to help maximize light output through reflection. Another consideration is the wall sheen. The halo effect works best when the wall has a semi-gloss or matte sheen. The use of a light-diffused plastic back or translucent vinyl will help spread out the halo effect.
Installation options
LED-illuminated letters can be either mounted directly onto a wall or mounted onto rails or raceways that allow them to project from a wall. The choice may depend on the following factors:
- The nature of the wall (i.e. whether it is flat or uneven).
- Local sign codes.
- Property-specific guidelines (e.g. if the sign is for a business within a shopping mall that specifies one option or the other).
- The electrical system (i.e. where and how the wiring will run).
- The size of the letters.
- The copy layout.
LEDs can be installed behind opaque letters for a ‘halo’ lighting effect.
Traditional neon-lit channel letters have to be mounted onto large raceways to contain their high-voltage wiring. Low-voltage LED systems do not have the same requirements and may instead use small raceways or rails. These can be bought or built.
Direct mounting to a wall is another option. It can be handled in much the same way as with non-illuminated dimensional letters, but—as when using raceway and rail systems—a wiring and power supply installation plan will need to be developed with a licensed electrical contractor.
All power supply holes will need to be located and drilled through. The holes might need to be centred, for example, to correspond with a raceway. For a UL-listed exterior sign, 6.4-mm (0.25-in.) ‘weep’ holes are also required in all letter drops. Face holes will need to be drilled to allow the faces to be attached to the cans.
It is important to keep in mind that even though low-voltage LED-lit letters require little electrical infrastructure, they are still subject to the same sign code rules affecting higher-voltage illuminated signs. Installers should study and understand all applicable electrical and sign code requirements.
Dan Wett is a technical adviser and writer for Gemini Canada, which manufactures plastic and metal letters, logos and plaques for the sign industry. This article is based on a seminar he presented at the United States Sign Council (USSC) Sign World International show in December 2011. For more information, visit www.signletters.com and www.ussc.org.
