I can completely understand why this question would be asked. After all the work a lighting designer goes through to create the right feel for a scheme, why would they then want to ruin it with 6000K (cool white) exit signs? As far as meeting the standards is concerned, there is certainly no requirement for cool white to be used for emergency signage. It is generally adopted simply because this colour of white LED provides the most light using the least power.
If a warmer white is required, there is nothing in the standards to stop this. However, there are three points to bear in mind:
- The light will be passing through a green filter rather than giving the true Kelvin colour temperature.
- You have a duty of care in your risk assessment to provide a clear escape plan. If this means providing a brighter and cooler light, then this must be your priority.
- Exit signs don’t have to be maintained (on all the time). If non-maintained, they will only come on when required, which means they won’t ruin the colour of the light.
Again, your risk assessment should tell you what is right here. If, for example, the scheme is a wine bar, customers who don’t know the layout should be able to locate the exits easily and plan their escape route as they enter the building.
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