Calculating average illuminance by capacity estimation method
Source: Date:2010-03-12 16:31:44
1/ Calculating average illuminance by capacity estimation method：Eav=（ФxNxCUxMK）÷A
Eav=Average illuminance
Ф=Luminous flux
CU=Utilization factor
MK=Maintenance factor
N=Number of lamps
A=the measure of area（m2）
2/ Example of average illumination design room of an office：
A/ Design conditions：
Office chief18.2m, wide10.8m, ceiling height2.8m, desktop height0.85m, utilization factor0.7, maintenance factor0.8, number of lamps33set, what is the average illumination in the office?
B/ Lighting solutions：
The lamp adopts stone light low nitDiNiT 2X55Wanti glare fluorescent lamp, luminous flux3000Lm, color temperature3000K, color renderingRa90above.
According to the formula listed in 1:
Eav=(33setX6000LmX0.7X0.8)÷(18.2mX10.8m)
Eav=110880.00÷196.56 m2
Eav=564.10Lx
C/ remarks：
The lighting design must require accurate utilization factor, otherwise there will be great deviation, which will affect the utilization factor, mainly due to the following factors:
*Light distribution curve of lamps
*Light output ratio of lamps
*Indoor reflectivity, such as ceiling, wall, work desk, etc
*Indoor index size
For complex regional lighting design, professional lighting design software shall be used for computer simulation calculation.
