Site logo

Electrical Engineering Academy

Cover image 1

7. Simple Calculation of Flood Light, Facade Light, Street Light & Signage Light-(Part-1)

SIMPLE CALCULATION OF FLOOD LIGHT, FACADE LIGHT, STREET LIGHT & SIGNAGE LIGHT-(PART1)

INTRODUCTION:

  • Outdoor Lighting can be classified according to the location where it can be installed or its function which use for highlight landscape area. * Outdoor Lighting can be classified as
  1. Flood Lighting, 2. Facade Lighting and 3. Signage Lighting 4. Street Light

(A) GENERAL OUTDOOR FLOOD LIGHTING:

  • Normally Pole mounted floodlights are used to illuminate general lighting area of parking lots and storage yards. * There are three factor should be consider while designing of outdoor flood lighting.
  1. Mounting Height. 2. Spacing 3. Aiming Distance. 4. Horizontal Aiming.
  1. Mounting Height:
  • Mounting height should be one half the distance across the area to be lighted. * If the area to be lighted is 16 Meter, the lowest recommended mounting height is 8 Meter. * Mounting height = 1/2 distance to be lighted * 1/2 (16 Meter.) = 8 Meter. 

1

  1. Spacing:
  • When more than one Luminar / pole is required than distance between two adjacent luminar / Pole is 4 times Mounting height of luminar /pole. * If the mounting height of luminar /Pole is 8 Meter than distance between adjacent Luminar is 32 Meter. * Pole Spacing = 4 x mounting height. * 4 (8 Meter pole) = 32 Meter between poles

2

  1. Vertical Aiming:
  • The fixture should be aimed 2/3 of the distance across the area to be lighted and at least 30 degrees below horizontal. * If the area to be lighted is 16 Meter across, the recommended aiming point is 10.6 Meter. * Aiming point = 2/3 Distance to be lighted. * 2/3 (16 Meter) = 10.6 Meter aiming point * To minimize glare, the recommended aiming point distance should never exceed twice the mounting height. * If a pole is 8 Meter high, the vertical aiming point should not exceed 16 Meter. * 2 (8 Meter mounting height) = 16 Meter. 

3

  1. Horizontal Aiming:
  • When two floodlights is mounted to a single pole then horizontal aiming also must be considered. * Each floodlight should be vertically aimed according to the two-thirds rule. * The floodlights should be aimed up to 90 degrees apart. 

4