Question 1) Average service illuminance of 300 lux is to be provided on the work plane (0.85m in height) in a classroom of dimensions 20m x 10m x 5m, using 80W, ceiling mounted standard fluorescent lamps. Determine the number and layout of the lamps required. Given: Utilization Factor of 0.5; Maintenance Factor of 0.8; S/Hm ratio = 1.5(max); luminous efficacy of the lamp = 160 lm/W.
Question 2)a) A room measuring 20 m × 10 m × 3 m is to be illuminated to 500 lux using ceiling mounted FTL luminaires of LDL = 2750 lm. Suppose UF = 0.55 and MF = 0.7. Design the lighting scheme if the working plane is at a height of 75 cm from the floor. Show the lamp disposition. Also, find out the initial value of Glare Index for lengthwise direction of view using the following table:
X Y GI
4H 10H 16.4
4H 12H 17.2
6H 10H 17.8
6H 12H 18.8
b) The front of a building 50m height and 15m wide must be illuminated by flood lighting projectors to a lux level of 200. The building surface is light coloured with brightly lit background during night time. The building surface has lot of projecting features. The flood lighting projectors are poorly maintained. Assume, U.F = 0.4. Lamps available are; Metal halide, 1000 watt, 80lm/w. H.P.S.V, 750watt, 120lm /w.
Suggest a appropriate lighting scheme and comment on the beam spread if the projectors are located 15m away from the building.
Question 3)a) With neat sketches, describe the basic types of lighting arrangement suitable for two-way traffic roads and dual carriage ways.
b) Mention six basic rules for achieving energy efficiency and cost effectiveness in lighting installations. Describe any two.
c) Describe the quality criterion of sports lighting with suitable examples.