A 5,000 square foot office area has 90 fixtures each with two lamps. The lumen output of each lamp is 2,800 lumens and they have a light loss factor of 0.7 and a coefficient of utilization of 0.75. A lighting retrofit is proposed that will reduce the total power required by installing lamps with an output of 2,400 lumens each, a light loss factor of 0.85, and a coefficient of utilization of 0.80. How many fixtures would be required so that the new lights provide the same number of footcandles as the existing lights?

A 5,000 square foot office area has 90 fixtures each with two lamps. The lumen output of each lamp is 2,800 lumens and they have a light loss factor of 0.7 and a coefficient of utilization of 0.75. A lighting retrofit is proposed that will reduce the total power required by installing lamps with an output of 2,400 lumens each, a light loss factor of 0.85, and a coefficient of utilization of 0.80. How many fixtures would be required so that the new lights provide the same number of footcandles as the existing lights?

Delmar's Standard Textbook Of Electricity

7th Edition

ISBN:9781337900348

Author:Stephen L. Herman

Publisher:Stephen L. Herman

Chapter18: Resistive-inductive Parallel Circuits

Section: Chapter Questions

Problem 1PA: Incandescent lighting of 500 W is connected in parallel with an inductive load. A clamp-on ammeter...

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