Fountain lighting design

Fountain lighting design

Light selection, light direction, color combination and coordination with water movement

Lighting determines how the fountain looks at night. A fixed blue composition can have different effects by changing the direction of radiation, intensity of light and color: calm and meditative, formal and majestic or dynamic and dramatic.

The quality of this experience does not depend on the number of lights. The light should reach the desired part of the water, be in harmony with the background and not disturb the audience and neighbors. Successful design also depends on installation conditions, thermal control, quality of connections and maintenance.

This chapter examines lighting as part of an integrated fountain design. Details of cable calculations, protection and electrical circuits will be completed in the dedicated chapter on electricity and safety.

18–1. Determining the purpose of lighting

Before choosing a lamp, it should be determined what the lighting is going to highlight.

In a still pond, the goal may be to display the water surface and reflect the architecture. In the waterfall, the continuity of the water curtain and the falling texture is important. In the musical fountain, the light should read the shapes and temporal changes of the show.

Three layers can be considered for the initial design:

• Water Light: Light up jets, waterfalls, curtains and other water effects.

• Lighting of architectural elements: showing the edge of a pond, a statue, a wall or a field that is related to water.

• Ambient lighting: providing proper visibility in the paths, seating and entry and exit points.

These layers must be coordinated. Public pathway lighting should not be dependent on the display being active; Also, the ambient light should not overpower the water effect without checking.

18–2. Power difference with optical performance

In the specifications of the lamp, several different quantities are mentioned:

Two lights with the same power can have different luminous flux, radiation angle and performance. Also, the luminous flux declared for the light state of all colors is not necessarily the luminous flux of each color alone.

To evaluate the fountain, it is not enough to measure luxury on a hypothetical surface; Water is not a fixed and opaque body and its appearance changes with the shape of flow, bubbles, drops, viewing angle and background.

Therefore, the choice should be made based on the optical information of the lamp, the geometry of the project and the evaluation of the sample. Terms such as "high power lamp" are not technical specifications without comparable data.

18–3. How does the shape of water affect lighting?

Clear water, air flow, scattered droplets and continuous curtain do not have the same visual behavior. The light should be tested on the actual shape of the water.

In a narrow jet, focusing the light along the jet is important. In bulk and airy flow, the goal may be to display volume and texture. In the water curtain, the position of the light relative to the screen and the location of the audience greatly changes the result.

For a calm waterway, lighting the floor, wall or adjacent element can be more suitable than shining light directly on the water surface; This choice depends on the purpose of the architecture.

The designer must distinguish between "lighting of water" and "directly visible light". Seeing a very bright source at the foot of the fountain does not necessarily mean successful lighting of its entire height.

Figure note from the source manuscript

Figure 1–18: Three photos with comparable shooting conditions of a narrow jet, air jet, and water curtain at night. Images should be selected from the real archive of projects. Suggested caption: "The shape of the water flow changes the way the light shines and the final effect."

18–4. Types of lights in terms of installation

The shape of the lamp should be in harmony with the position of the nozzle, architectural details and maintenance conditions.

In the GSO lighting collection, the Prolight, Proclass and Proflat families are introduced, along with round nozzle, pedestal, recessed and surface mounted variants. Choosing between these families should be done by checking the specifications of the desired model. GSO urban fountain lights ^[102]

A built-in or round-nozzle light is not suitable for every traversable surface or every nozzle, simply because of its appearance; Installation details and product limitations must be accommodated.

18–5. Irradiation angle and light coverage

A narrow beam focuses light into a narrower area; Open beam covers a wider area. The choice between them should be made based on the shape of the target and the distance of the light.

For basic geometric understanding, the cross-sectional diameter of an ideal conical beam is obtained from the following equation:

$D=2L\tan (\frac{\theta }{2})$

In this regard:

• $D$ : diameter of the beam section;

• $L$: distance from the assumed origin of the beam along its axis;

• $\theta$ : full beam angle.

For example, if the full angle of the beam is 20 degrees and the distance is 2 meters:

$D=2\times 2\times \tan (10^{°})\approx 0.705m$

So, the approximate geometric diameter of the beam is about 71 cm.

This example is just an educational geometric model. The actual distribution of light does not have a sharp boundary, and the angle declared by the manufacturer is also measured with a certain definition. The light passing through the glass and the water-air boundary, light refraction and the changing shape of the fountain are not included in this calculation. From this relationship, it is not possible to determine the height that can be illuminated or the exact number of lights.

Figure note from the source manuscript

Figure 2–18: Schematic of two equally spaced narrow and wide beams, with complete angle and cross-sectional diameter shown. Suggested caption: "Choosing the angle of incidence determines the balance between focus of light and extent of coverage." Put the title "Educational Geometric Model" on the image.

18–6. Placement of the lamp in relation to the nozzle and the audience

Placement should be done both in the plan and in the section. In the plan, the relationship of the lamp with nozzles and observation points is examined; In the cross-section, installation depth, radiation direction, water height and the possibility of directly seeing the light source are determined.

For each blue group, you should ask:

• Does the beam reach the main part of the stream?

• Does the nozzle, pipe or structural piece cast a shadow?

• Does changing the height of the water take part of the effect out of the light range?

• Is the audience looking directly at the lamp from the opposite side?

One light for each nozzle is not a general rule. Some compositions require several radiation directions; In others, a light can cover more than one segment.

In a moving nozzle, the range of motion must match the range of light. The proper brightness of the jet in the upright position does not guarantee its proper performance at other angles.

18–7. White light, RGB and RGBW

The choice of color system should follow the operating scenario.

Fixed white light can be considered for designs that aim to emphasize water form, architecture or a sustained nighttime effect.

RGB creates different colors by combining red, green and blue channels. The result depends on the characteristics of light sources, optics, settings and mixing methods.

RGBW also has an independent white channel. This channel can be useful for making white scenes and some color combinations; However, the quality of white light should be checked from the specifications of the same product.

Adjustable white allows the white color temperature to be changed within the specified range of the product and is not equivalent to the production system of all colors.

For example, Crystal Fountains introduces RGB, RGBW, warm white, cool white and adjustable white options in the LED160 family. The existence of these options shows that the type of light should be specified in the product order. Specifications of the LED160 family ^[103]

Color temperature is used to describe white light; Attributing it to saturated colors like red or blue is not a good way to compare.

18–8. Stage design and light coordination with water movement

It is suggested to define some clear and exploitable states instead of programming only based on continuous color change:

This table is the suggested template of the book and should be adjusted for each project.

In a show, light can highlight a group of water, create a transition of attention, or accompany a change in the height of a fountain. Lighting all groups at maximum intensity all the time limits the ability to create emphasis and contrast between scenes.

Very fast changes and flashing should not be the default setting of public space. The speed of change, intensity and type of effect must be coordinated with the location, audience and relevant criteria.

18–9. Light control and coordination with the fountain system

The control system must provide the possibility of performing the required scenes. The term "controllable" alone is not enough; It must be specified what is controlled independently: each lamp, each group or the whole set.

Also, the number of channels cannot be deduced from the RGB or RGBW name alone. Some equipment has channels for general intensity or other functions in addition to color. The addressing map should be prepared based on the actual control mode of the product.

In the initial design, these should be clear:

• Controller protocol and compatibility, driver and lights;

• Number of independent groups and channels;

• behavior during disconnection;

• the order of turning on and returning after a power cut;

• Coordinating the light with stopping or changing the state of the water.

Support for protocols such as DMX or RDM should also be checked throughout the equipment chain. Networking, addressing and programming details will be explained in the control systems chapter.

18–10. Reduce glare and annoying light

Glare can be caused by direct viewing of the light or its reflection on water and shiny surfaces. Inspection should be done from the place of standing, sitting, passage and visible buildings.

Correcting the beam angle, moving the light, choosing the right optics and reducing the intensity can be effective. The use of cover or light barrier should also be compatible with the thermal conditions and the lamp installation order.

The joint DarkSky and Lighting Engineering Society guidelines emphasize aiming light, directing it, limiting intensity, controlling time, and reducing shortwave light where possible. Principles of responsible outdoor lighting ^[104]

The application of these principles in the fountain requires attention to upward radiation. Even if the goal is to illuminate the jet, some of the light may pass through the water; This situation should be checked again when the height of the fountain is reduced or the water stops.

Figure note from the source manuscript

Figure 3–18: Two training images of the same layout; First, the light source should be in the audience's view, and secondly, the radiation angle should be corrected. Suggested Caption: "Controlling the direction of radiation increases the readability of water and limits the direct view of the light source."

18–11. Degree of protection, installation conditions and heat control

The IP degree of protection is part of the specification of the lamp. This rating alone does not prove compatibility with water chemicals, corrosion, impact, transient load or thermal conditions.

For submersible lights, the allowed immersion depth and conditions, type of cable and connection, working temperature, and allowed water quality should be extracted from the manufacturer's documentation.

Also, a light suitable for underwater installation is not necessarily suitable for working outside of water. Some models depend on specific installation conditions for heat dissipation.

For example, in the ProfiRing LED L family, OASE introduces the possibility of dry and submerged installation with reference to internal temperature control. This feature is specific to the introduced product and should not be extended to all IP68 lights. Specifications of ProfiRing LED L ^[105]

In the dry floor fountain, the working conditions of the lamp when the fountains are off should be checked explicitly.

In terms of technical reference, IEC 60598-2-18 deals with fixed lights used in or in contact with water, including fountains; IEC 60364-7-702 is also a reference related to the electrical installations of pools and fountains. The compliance of the project must be checked with the applicable regulations and the valid version of the documents. 24V or IP68 rating alone is not a complete confirmation of system safety. Standard scope of lights ^[106], electrical installation reference ^[107]

18–12. Calculation example of power and energy consumption

Suppose a training plan includes the following equipment:

The numbers are hypothetical and do not belong to a specific product. It is assumed that the power of each lamp is the maximum input power at the power supply terminal.

If all lights are powered by 24V DC:

$I_{total}=\frac{P_{total}}{V}=\frac{528}{24}=22A$

The number 22 amperes is the total current of loads in the assumed conditions; This number does not mean feeding all the lights from one circuit or one cable.

To estimate energy, let's assume that the effective power conversion efficiency is 90% and the consumption of independent control equipment is 20 watts:

$P_{input}=\frac{528}{0.90}+20\approx 607W$

With daily operation of 5 hours and 300 days a year:

$E=\frac{607\times 5\times 300}{1000}\approx 910\mathrm{kWh/year}$

This estimate is for operation at the assumed power and does not include the consumption of pumps. Cable losses are not considered in this example and should be added in the detailed estimate.

A decrease in intensity or color change may alter consumption; But the percentage of light reduction command is not necessarily equal to the same percentage of power reduction. For more accurate calculation, measured power or manufacturer data for different scenes should be used.

The selection of the power supply capacity is also dependent on the installation temperature, the allowable capacity reduction, the starting current, the expected development and the manufacturer's instructions; A fixed coefficient is not enough for all projects.

18–13. Technical specifications required for purchase

In the purchase documents, each lamp model should be introduced with clear specifications. The minimum required information is:

• Exact code, number and place of use;

• Type of light and color option;

• input power and its measurement conditions;

• compatible supply voltage or current and driver;

• Optical flux, radiation angle and available light distribution data;

• Dimensions, base type and adjustment range;

• Permissible working conditions in and out of water;

• Material of body, cable, seal and connections;

• protocol and control mode;

• Replacement method, spare parts and warranty conditions.

If the life of the LED is declared, the test conditions and light loss criteria should also be specified. The life of the light source is not the same as the full life of the lamp, driver, cable and seal.

18–14. Night setting and delivery criteria

Lighting delivery should be done in real night conditions, with running water and normal ambient lighting. Testing the lights in the workshop is not enough to confirm the visual result of the site.

The proposed evaluation includes the following:

Acceptable criteria and limits should be defined in the project documents prior to delivery.

The recorded photo depends on the exposure and white balance of the camera; Therefore, a beautiful picture is not a substitute for a visit and test. For comparison, photographic settings should be recorded and kept as constant as possible.

Figure note from the source manuscript

Figure 4–18: Night setting registration page including overview, number of lights on plan, and close-up of adjustable base. Suggested Caption: "Registering angles, groupings and final adjustments makes it easy to restore light quality after repair." Include a photo of the actual project with the company's approved name and role.

18–15. Maintenance of light quality over time

The quality of lighting may gradually decrease due to sediment on the glass, changing the angle of the lamp, turbidity of the water or the failure of a color channel. Before increasing the light intensity or replacing the whole set, the cause of the quality loss should be investigated.

The maintenance program should include cleaning according to the method compatible with the product, inspection of joints and seals, inspection of foundations and comparison of reference scenes. The replacement light must also be adapted to the existing set in terms of optics, color and control method.

The final delivery documents should include the lights numbering plan, specification table, power and control plan, program file and maintenance order. These documents provide the possibility of maintaining the design result during the operation period.

In chapter 19, the sound and acoustics of the fountain are investigated; From the natural sound of falling water and its effect on the urban environment to the placement of speakers, the clarity of music and the control of noise disturbance.