This method is used to calculate the average illuminance by coefficient method.
Light flux (CU) maintenance factor (MF)/ irradiation area
Utilization coefficient (CU): generally, indoor value is 0.4, and outdoor value is 0.3.
The maintenance coefficient MF=(LLD)X(LDD) is generally 0.7 ~ 0.8.
Example 1:
Indoor lighting, 4× 5m room, 10 sleeve lamp, 2.5 inch 8W energy-saving lamp T428W2.
Average illuminance = total luminous flux of light source ×CU×MF/ area
=(40×8× 10+ 100*28*2)×0.4×0.8÷4÷5
= 140.8 lux
Conclusion: The average illumination is above 120Lux.
General office space lighting requirements:
Hall 300
Elevator room 200
Corridor 200
Office area 300
Meeting area 300-400
Reception area 300