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. 

2) 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

3) 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. 

4) 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.