Hi,

I guess that the following publication could answer your question:

http://www.iar.unicamp.br/lab/luz/ld/Arquitetural/diversos/Lighting%20for%20Libraries.pdf

The different parts of the library are exposed differently to light. The collection, for instance, should not be exposed to direct daylight.

Hello!

Please check here for the level ranges: https://www.lightingassociates.org/i/u/2127806/f/tech_sheets/Natural_Lighting.pdf

Here you can find some hints about glare calculations, and recommendations how to evaluate it annually: https://www.radiance-online.org/community/workshops/2014-london/presentations/day1/Wienold_glare_rad.pdf

Hope it helps!

Dear Fatima Belok,

You can check this link Article Average daylight factor for the ISO/CIE Standard General Sky

Which says...

"The average daylight factor is one of the most widely used methods for predicting the internal luminescence due to daylight. It is a simple tool that can be used in the early stages of design and can give information about the luminous environment inside a room. This method is supposed to be used under overcast sky conditions. Expanding the use of the average daylight factor to other sky conditions will encourage the use of daylight in buildings. Several methods have been proposed for the prediction of daylight based on the CIE Standard General Sky. However, most of these methods aimed for a detailed estimation of the internal luminescence pattern."

Thank you all for your replies, I really appreciate it

I have another question if someone could help me to find the answer:

how could I know when the level of illuminance is uncomfortable ?, for example for the LIBRARY the illuminance need it is 500 lux so if it is less then 500 it is non sufficient (illiminance not good)  , sot it should be 500 or greater (illuminance >500lux  --> good ) but what is the limit of the lux that is good for the visual comfort ??

Best Regards