The room is 38.5m2, with luminous flux 1200lm, average illumination of 300lx, space utilization coefficient of 0.7 and maintenance coefficient of 0.8. Ask how many lights there are in the room and how

The room is 38.5m2, with luminous flux 1200lm, average illumination of 300lx, space utilization coefficient of 0.7 and maintenance coefficient of 0.8. Ask how many lights there are in the room and how many watts per square meter. The answer process is as follows:

(1), number of lamps required:

n = e * a/(φ*η)= 300 * 38.5/( 1200 * 0.7 * 0.8)= 17. 1。

Round N= 18 (calculated by luminous flux 1200lm, the power of the lamp is about 1 1w).

(2), the power per square is

LPD= number of lamps * lamp power/room area =18 * (11+2)/38.5 = 6.077w/m?

Note: Lamp power = light source power+electric power.