Hello,

I have a few regularly occupied lab spaces with suspended lights at around 12'-8".  There is no ceiling in the space and the structure goes up to around 20'-0". 

For Strategy H, I am not sure how to calculate the ceiling illuminance when there is no ceiling in the space.  I can put my calc plane in the DIALux model at the same height as the fixtures, but I feel that is not really surface illuminance.  On the other hand, if I calculate all the way up at the structure, I feel it is not representative of the ceiling to work surface ratio.  

Hoping someone has come across this situation and can provide guidance.

Thank you!