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Lumen Method Lighting Calculator
Calculate number of luminaires needed using the zonal cavity (lumen) method.
Room Area
?
Floor area of the room.
sq ft
Target Illuminance
?
Required foot-candles at work plane.
fc
Lumens per Fixture
?
Initial lamp lumens per fixture.
lm
Coefficient of Utilization
?
CU from manufacturer tables (0.4-0.8 typical).
Light Loss Factor
?
Combined maintenance/depreciation factor (0.6-0.9).
Calculate
Results
Total Lumens Required
-
lm
Number of Fixtures
-
Actual Illuminance
-
fc
References:
IES Lighting Handbook; IESNA LM-79; CIE 97:2005