PE Power Sample Problem 2

The lobby of a hotel is 200ft (W)×100ft (L)×30 ft (H). Target illumination level for the lobby is 50fc. The selected luminaire for this application has 8 lamps and each lamp has an output of 750 lumens. The luminaires will be mounted at a height of 25 ft from the floor and working plane will be 3 ft from the floor. Lamp lumen depreciation factor is 0.90, luminaire dirt depreciation factor is 0.85, coefficient of utilization is 0.80, wall luminance coefficient is 0.25, ceiling cavity luminance coefficient is 0.30 and room position multiplier is 0.75. The minimum number of luminaires that will be required for this application are _____.
(A) 273
(B) 235
(C) 213
(D) 297

Wasim Asghar – P.E, P.ENG, M.ENG

Licensed Professional Engineer in Texas (PE), Florida (PE) and Ontario (P. Eng) with consulting experience in design, commissioning and plant engineering for clients in Energy, Mining and Infrastructure.