calculating number of fixtures needed
I am putting together my kitchen lighting layout and have seen posts on this forum that talk about ~35 lumens per square foot as a guide to calculate how many fixtures to use.
The question I have is do people just use the advertised lumens on the light, or do they factor in the coefficient of utilization (CU) to determine effective lumens?
For example, I have read that the best coefficient of utilization to use for the Cree LR6 is 0.77. Essentially that means that about 77% of the luminous output of the light effectively hits its surface.
When I factor in the CU, it increases the number of lights I need by about 30%.
Or are there free tools out there which let you model your room layout and and fully calculate fixtures based on the Lumen Method?