Outdoor Lighting Design Calculations – Part Two

In the previous Article " Outdoor Lighting Design Calculations – Part One ", I indicated that The outdoor lighting can be classified according to application as follows:

  1. General lighting, 
  2. Accent lighting, 
  3. Orientation lighting, 
  4. Floodlighting, 
  5. Street & Roadway lighting, 
  6. Sports lighting. 

And I explained the first three types in this previous article.

Today, I will continue explaining other types of outdoor lighting based on application as follows.

Fourth: Floodlighting

Floodlighting is generally used in (5) types of lighting design which are:

  1. Facade lighting (wash lighting), 
  2. Wall washing lighting, 
  3. Signage lighting, 
  4. Area lighting, 
  5. Vegetation. 

1- Facade lighting (wash lighting):

  • Facade definition: Typically, the front of a building, facing a public street or road. 
  • Wash lighting is probably the most common use for Flood lights. 
  • Wash lighting forms the background for accent lighting for emphasising objects. 
  • Wash lighting facades allow them to appear in their entirety. 
  • Wash lighting illuminates larger objects or spatial zones using wide beam light distribution. 
  • The Wash lighting can be positioned on the ground, on a mast or on the building. 
  • In contrast to accent light, it conveys a wide impression. Wash lighting enables safe movement on pathways and effectively highlights large objects and areas. 
  • The form of facades is determined not only by their material and shape but also by the following factors: 
  1. Changing direction of light, 
  2. Varying components the luminaries between diffuse and direct light, 
  3. Different light distributions, 
  4. The use of lighting control systems, 
  5. Varying illuminances differentiate components or areas of a facade. 

Forms of facade:

The used lighting technology will differ according to the different Types of façade, which are:

  1. Solid façade, 
  2. Facade, vertically divided, 
  3. Horizontally divided façade, 
  4. Facade with projecting or recessed sections, 
  5. Perforated façade, 
  6. Banded façade, 
  7. Transparent façade. 

1.1 Solid facade

We have (5) scenarios for wash lighting a solid façade:

  1. Floodlight, below: creates a very uniform light distribution on the façade. 
  2. Line of light, above: marks out the edge of the building against the night sky. 
  3. Uplights: rhythmically divide up the facade. 
  4. Facade luminaries downlights. 
  5. Facade luminaries uplights and downlights. 

Arrangement for solid façade lighting: 

we have (6) arrangements for lighting solid facade as follows:

  1. Recessed floor luminaries, 
  2. Surface-mounted floor luminaries, 
  3. Upright supporting tube, 
  4. Mast, 
  5. Cantilever arm, 
  6. Facade luminaries. 

Recommendations for lighting a solid Facade: 

  • Luminaries positioned close to the façade produce Grazing light emphasises the surface textures of facade materials. 
  • Wash lighting facades can make them appear flat. Reducing the illuminance as the facade height increases gives a low-contrast transition to the dark night sky. 
  • Wall washers offset from the facade at one third to half the facade height avoid long shadows. 
  • Wash lighting creates a very uniform light distribution on the facade. Shining any light beyond the facade surfaces, either to the sides or over the top, should be avoided. 
  • Mast luminaries will appear as additive features in front of the facade. 
  • Recessed floor luminaries are architecturally discrete. Overgrown vegetation must be prevented. 

1.2 Facade, vertically divided

We have (5) scenarios for wash lighting a Facade, vertically divided: 

  1. Floodlights: Floodlights produce a uniform illumination on the facade. Wash lighting with point-shaped light sources makes the surface texture and structure clearly visible. 
  2. Uplights: Accentuating the columns detaches these from the surrounding facade 
  3. Uplights, double-sided layout: Uplights positioned on two sides emphasise the volume of the column 
  4. Downlights: Downlights accentuate the column and illuminate the floor area. 
  5. Downlights and uplights: The combination of uplights and downlights augments the vertical facade division by lighting from above and below. 

Recommendations for lighting a Facade, vertically divided: 

  • Narrow beams of light intensify the effect of the vertical division. 
  • To avoid shadows at the side, the luminaries should be positioned at right angles, parallel to the facade. 
  • Strong contrasts and heavy shadow can be compensated for by wash lighting the facade as a form of general lighting. 
  • The luminaries should be positioned in a rhythm corresponding to that of the façade divisions. 

1.3 Horizontally divided facade

We have (2) scenarios for wash lighting a Horizontally divided façade:

  1. Floodlights: illuminate the entire facade and emphasise the horizontal divisions by casting heavy shadows. 
  2. Lines of light: echo the horizontal structure on the darker facade surface. 

Recommendations for lighting a Horizontally divided facade: 

  • Luminaries positioned close to the facade highly emphasize its three-dimensional nature. 
  • Long heavy shadows cast by facade divisions can be reduced by increasing the offset of the luminaire from the facade. 
  • The steeper angle of incidence for the light in the upper region of the facade casts longer shadows than in the lower area. 

1.4 Facade with projecting or recessed sections

We have (4) scenarios for wash lighting a Facade with projecting or recessed sections: 

  1. Floodlights: Wide-beam floodlights set far from the building illuminate the facade evenly. 
  2. Spotlights with different illuminances. 
  3. Spotlights with different light colors. 
  4. Uplights: mark out the internal corners with grazing light. 

Recommendations for lighting a Facade with projecting or recessed sections: 

  • Facades with large protruding sections or insets will feature heavy shadows. 
  • Different illuminances or light colors augment the differentiation of the facade. 
  • Differentiated illuminances, light distributions and light colors add rhythm to the appearance of the facade. 
  • Harsh contrasts between accentuated and unlit areas can be compensated for by using wash lighting to perform the general lighting. 
  • Increasing the luminaire offset from the facade reduces the formation of heavy shadow. 
  • The luminaire arrangement should correspond to the pattern of facade division. 

1.5 Perforated facade

We have (5) scenarios for wash lighting a Perforated facade: 

  1. Daylight: Under daylight conditions the window surfaces appear dark. 
  2. Downlights, indoor. 
  3. Floodlights: Floodlights produce uniform light distribution over the facade. 
  4. Lines of light: Illuminating the window embrasure accentuates the frame of the facade opening. 
  5. Uplights: narrow-beam uplights emphasise the facade‘s grid pattern. 

Recommendations for lighting a Perforated facade: 

  • At night, illuminated interiors provide a strong contrast between the dark facade surface and bright windows. 
  • Indoor users should not be dazzled. Luminaires shining into the interior impair the view out of the building. 
  • Lighting control systems can be used to control the light in individual rooms and to create patches of light on the facade. 

1.6 Banded facade

We have (3) scenarios for wash lighting a Banded facade: 

  1. Daylight: Under daylight conditions the strip of windows appears dark. 
  2. Uplights, indoor. 
  3. Band of light: The lighting on the balustrades augments their horizontal structure. 

Recommendations for lighting a Banded facade: 

  • Illuminating the indoor areas at night forms a strong contrast between dark facade surfaces and a bright strip of windows. 
  • The strong contrast between bright indoor lighting and the dark outer surface at night can only be compensated for to a small extent with facade wash lighting. 

1.7 Transparent facade

We have (5) scenarios for wash lighting a Transparent facade: 

  1. Daylight: Under daylight conditions, the transparent facade appears dark and reflects its surroundings. 
  2. Downlights, indoor: Ceiling wash lights in the indoor area emphasise the ceiling surfaces and increase the overall impression of interior brightness at night. 
  3. Uplights, indoor. 
  4. Lines of light : used in the ceiling area of the individual floors underline the horizontal building structure. 
  5. Uplights, outdoor: emphasise the vertical elements of the facade. 

Recommendations for lighting a Transparent facade: 

  • The facade construction is silhouetted. 
  • Indoor lighting allows the observer to see into the building. 
  • The visual perspective from the ground makes the lighting effect of the indoor area appear larger with uplights than with downlights. 
  • Dazzling the users of the indoor area should be avoided. 
  • Luminaries shining into the indoor area will impair the view out of the building. 

Preferred luminaries for using with Façade lighting (wash lighting):
  1. Wash lighting Floodlights,
  2. Facade luminaries.

1- Wash lighting Floodlights 

Floodlights have a wide-beam characteristic. They are offered with a axially symmetrical or asymmetrical light distribution.

Criteria for floodlights:
  • Choice of lamp determines light color, functional life, efficiency, light intensity 
  • Uniformity: optimized reflector for even illumination of areas 
  • Gradient: soft edge to the beam of light 
  • Light output ratio is increased by optimized reflector technology 
  • Floodlights with axially symmetrical light distribution provide even illumination of objects or areas. Light distribution with focal emphasis. 

2- Facade luminaries

Facade luminaries are offered with narrow-beam, wide-beam, symmetrical or asymmetric light distribution. The light can be distributed either via a single-sided or double-sided light aperture.

Applications of Facade Lighting (wash lighting):
  1. Wall lighting 
  2. Facades 
  3. Entrance areas 
  4. Cantilever roofs 
  5. Trees 
  6. Park and garden complexes 
  7. Sculptures 
  8. Objects 
  9. Preferred luminaire group 
  10. Floodlights 

In the next Article, I will explain the Other Types of Flood Lighting. Please, keep following.