Calculation method of illuminance of LED fluorescent tube
The following method can be used to roughly calculate the illuminance value
Illumination calculation method Use coefficient method to calculate average illuminance
Average illuminance (Eav) = total luminous flux of light source (N*Ф)*utilization factor (CU)*maintenance factor (MF) / area area (m2) (applicable to indoor or stadium lighting calculation)
Utilization factor: 0.4 for general indoor and 0.3 for sports
Maintenance factor: generally 0.7～0.8
Example 1: Indoor lighting: 4×5m room, using 9 sets of 3×36W grid lights
Average illuminance = total luminous flux of light source×CU×MF/area
＝(2500×3×9)×0.4×0.8÷4÷5
＝1080 Lux
Conclusion: The average illuminance is above 1000 Lux
Example 2: Stadium lighting: 20×40m venue, using 60 sets of POWRSPOT 1000W metal halide lamps
Average illuminance = total luminous flux of light source×CU×MF/area
＝(105000×60)×0.3×0.8÷20÷40
= 1890 Lux
Conclusion: The average horizontal illuminance is above 1500 Lux
An office average illuminance design case:
Design conditions: The office is 18.2 meters long, 10.8 meters wide, the ceiling height is 2.8 meters, the desktop height is 0.85 meters, the utilization factor is 0.7, the maintenance factor is 0.8, and the number of lamps is 33 sets. What is the average illuminance in the office?
Lamp solution: The lamp adopts DiNiT 2X55W anti-glare daylight lamp with a luminous flux of 3000Lm, a color temperature of 3000K, and a color rendering property of Ra90 or more.
According to the formula:
Eav = (33 sets X 6000Lm X 0.7 X 0.8) ÷ (18.2m X 10.8m)
= 110880.00 ÷ 196.56 m2
= 564.10Lux
