Hi
I have a question regarding the external signage requirement. Our project plans to have a totem signage with digital display. Does this need to meet the requirement as specified by LEED i.e do not exceed a luminance of 200 cd/m2 (nits) during nighttime hours and 2000 cd/m2 (nits) during daytime hours or is this only required for signage illuminated by fixture/luminaires ?? My concern is that for the digital signage to be visible in the sun, generally 5,000+ nits is recommended... Please advise..
Bill Swanson
Sr. Electrical EngineerIntegrated Design Solutions
LEEDuser Expert
731 thumbs up
May 6, 2019 - 9:00 am
Yes it does.
Digital display signs are the easiest to document because they have information about nits. They also tend to be the worst type of internally illuminated signs for light pollution.
Personally, I think the daytime limit should be outside of the scope of this credit. But it is in the credit for now and should be complied with. Please comment during LEED updates to help shape the credit when you see a need for change.
Neetika Parmar
Senior Engineer-Sustainable Development9 thumbs up
May 7, 2019 - 2:18 am
Thanks Bill.
So, the external signage must not exceed luminance of 200 cd/m2 (nits) during nighttime hours and 2000 cd/m2 (nits) during daytime hours but can be excluded for calculating uplight and light tresspass requirements ? is my understanding of the credit correct ?
Bill Swanson
Sr. Electrical EngineerIntegrated Design Solutions
LEEDuser Expert
731 thumbs up
May 8, 2019 - 8:35 am
Correct. Internally illuminated signage is exempted from uplight and light trespass requirements.
Francesco Passerini
engineer90 thumbs up
September 11, 2019 - 6:00 am
Hello, is a totem signage (supermarket) considered a "specialized signal"? What is the definition of "specialized signal"?
I see that "specialized signal" is among the "Exemptions from Uplight and Light Trespass Requirements".
In this moment I don't know whether it will be internally illuminated or externally illuminated.
Bill Swanson
Sr. Electrical EngineerIntegrated Design Solutions
LEEDuser Expert
731 thumbs up
September 11, 2019 - 8:37 am
There are not many definitions for these terms. Specialized signal is meant for guiding of vehicles. Think of an airport. There are lights that mark the edge of the runway, lights for guiding the planes between the runway and the terminal, lights for right-of-way, flashing red lights on top of structures. These are lights that signal information to the person operating the vehicle for the safe operation of the vehicle. These lights are often specialized for the purpose they serve and are not just a normal light fixture.
Unique signage for a business is marketing, and would be considered signage.
Francesco Passerini
engineer90 thumbs up
September 11, 2019 - 9:42 am
Thanks.
Therefore is the totem signage (supermarket) not considered a "specialized signal"?
In this case we have two scenarios:
- if the totem signal is externally illuminated then it shall comply with Uplight and Light Trespass Requirements
- if the totem signal is internally illuminated then it is exempted from Uplight and Light Trespass Requirements, but it shall comply with the cd/m2 requirement
Do you agree?
Bill Swanson
Sr. Electrical EngineerIntegrated Design Solutions
LEEDuser Expert
731 thumbs up
September 11, 2019 - 11:31 am
Your totem signage is signage. It is not a "specialized signal".
Yes, those are the two options. But you will have difficulty documenting compliance for both options.
- externally illuminated will likely have too much uplight and glare. Calculate what % is blocked by the sign, and what's not.
- internally illuminated will not have data available for cd/m2. I have only gotten this information from video screens.