This is a specific formula, according to the illuminance requirements and the length and width of the room can initially determine the number of lamps and lanterns, and then according to the number of lamps and lanterns calculated with the power density to verify that the load density requirements of the value can be. If there is a Tianzheng electrical above also comes with the calculation of the number of lamps and lanterns.

The specific formula is as follows:

E = NΦUK / A

N = EA / (ΦUK)

Which:

Φ-- luminous flux lm

N -- the number of light sources

U -- Utilization Factor

A -- the work surface area of m2

K -- the fixtures Maintenance factor