Lumen Method for Lighting Calculation.

The lumen method is a technique used to determine how many luminaires (artificial light fixtures) are needed in a space to achieve the desired level of illumination, measured in lux (lumens per square meter).

🔢 Basic Formula:

Where:

• N = Number of required luminaires
• E = Required illuminance level (in lux)
• A = Area of the room (in square meters)
• F = Luminous flux per luminaire (in lumens)
• UF = Utilization factor (depends on room and fixture type)
• MF = Maintenance factor (accounts for light loss over time)

🧮 Calculation Steps:

1. Determine the recommended lighting level based on the room usage (e.g., 500 lux for office work).
2. Calculate the area of the room (length × width).
3. Find the luminous flux of each luminaire (from the manufacturer).
4. Use UF and MF values from technical tables or manufacturer guidelines.
5. Plug into the formula to calculate N.