2) A building has 500 lighting fixtures with operating power of 200 Watt/fixture

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2) A building has 500 lighting fixtures with operating power of 200 Watt/fixture. The lighting system operates 3,500 hours per year. An energy audit results in retrofit with 500 fixtures with operating power of 120 Watt/fixture and use of occupancy sensors that reduce lighting operation to 2,000 hours per year. If energy costs a flat rate of $0.10 per kWh, how much will the project save annually?

a) $12,000

b) $14,000

c) $21,000

d) $23,000

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1) Assume that a lighting system serving a 12-meter by 10-meter room uses 20 uniformly spaced fixtures each having two 3000 lumen lamps. Assume that the combined light-loss factor (LLF) is 0.65 and the Coefficient of Utilization (CU) is 70%. What would be the average illuminance in lux at the task (work surface)? (L)

a) 455

b) 500

c) 575

d) 600

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