Dry-deck fountains

Dry-deck fountains

Multipurpose space design, hidden equipment, water collection and operational requirements

A dry floor fountain displays water from or near the floor surface; While the open and permanent pond, like common fountains, is not seen on the surface of the area. Nozzles, lights and an important part of the installation are placed in the floor, local compartments or the space below it, and the outflow water is collected through the foreseen paths.

This structure can provide the possibility of different use of an urban space: the area can be used as a water display during the execution time, and after the surface water is stopped and drained, it can be used for passing, pausing or some events.

However, the quality of a dry floor fountain depends on many unseen details: floor slope, discharge capacity, retaining structure, sealing, maintenance access, water quality, and interdisciplinary design coordination.

9–1. What is meant by "dry floor"?

The term "dry floor" describes the way the fountain is placed. When running the fountain, the floor of the spraying area gets wet, and after stopping, its complete drying depends on the drainage, surface material and environmental conditions.

The main feature of this fountain is the absence of a permanent open pool on the usable surface of the area. The storage tank can be located under a part of the floor or in another place; Therefore, it is not necessary to build the entire surface of the fountain on a large tank.

Also, dry floor is not a control method. Such a water feature can be static, rhythmic, musical or interactive.

In GSO products, special nozzles for installation in stone pavement, types of comet and foam outlets, mobile lights and chamber packages have been introduced. Model selection and installation details should be done based on the specifications of the same product and project design. Source: GSO dry floor fountain equipment ^[47]

9–2. The first decision: water display or direct contact of people?

Before the design, it should be clarified whether the entry of people into the active area of the fountain is part of the project's use or not.

The appearance of a dry floor fountain may invite people to enter. If logging occurs frequently, this behavior should be factored into project evaluation and management.

CDC guidance also emphasizes that a decorative water feature used by the public for recreational use must be managed in accordance with this use or access to it must be effectively restricted. This guide is an international reference; The implementation requirements of each project must be adapted to the regulations and the responsible authority of the place. Source: Guide for using CDC water fountains ^[48]

The change of use from display to water amusement is not done only by reducing the height of the fountain or changing the control program; The entire system must be checked for a new user.

Figure note from the source manuscript

Figure 1–9: Two independent, real photographs from the GSO archive; One is a demonstration dry floor fountain and the other, if there is an approved project, is a fountain designed for direct contact with users. Suggested caption: "Similar appearance does not necessarily mean identical usage and requirements." The actual use of each project should be specified in the subtitle.

9–3. Make the main makeup

Dry floor fountains can be implemented with several arrangements:

Structural floor or removable parts on the concealed basin

Water returns to the collection space under the floor through openings or designated paths. This arrangement can provide proper access to the equipment, provided that the parts, supports and service path are designed from the beginning.

Integrated floor with local compartments and separate tank

Each nozzle or set of nozzles and lights is installed in a housing. Surface water is transferred to the tank through the salt flats, grooves or channels. In this method, adjusting the levels and coordinating the underground routes is very important.

Modular units

A part of the equipment is ready for installation and service in the form of a unit. This method can make it easier to replace some components, but still requires the design of the floor, structure, sealing and water collection.

For example, Crystal Fountains has introduced a suspended floor-mounted system where the pump assembly and equipment can be installed and removed from a designated opening. This example shows the importance of predicting the exit route of the equipment for repair. Source: Crystal Fountains Slab Hanger System ^[49]

9–4. Hidden components below the surface

For a complete review of the design, it is better to see the components of the dry floor fountain in five sections:

These sections should be designed based on a baseline. The difference between the architectural plan and the installation of the equipment can cause the plates to stick out, water stagnation, or the position of the nozzle being inappropriate.

The coordinated drawing shall specify the final level of the floor, nozzle opening, collecting rim, chamber floor and tank working surfaces.

Figure note from the source manuscript

Figure 2-9: Schematic cross-section of two arrangements; "Floor over concealed basin" and "Positional cabinet with separate tank". The route of water exit and return, sealing and service access should be determined. Suggested subtitle: "The choice of subfloor structure affects the implementation of the structure, water collection and maintenance." The image should be presented without prescribed dimensions and with the title "educational schematic".

9–5. Placement of nozzles and spray range

Placement should consider both the image of the water and the behavior of the site.

In addition to the distance of the nozzles, the area of water landing, the effect of wind, the path of passage, the place of sitting, the entrance of the buildings and the surrounding equipment should be checked. Higher altitude can change spray range and sensitivity to wind; This range should be evaluated for true effect.

In an accessible fountain, the position of the outlet relative to the user's body, the possibility of the face approaching the nozzle, and the possibility of the opening being blocked are also important in the selection of equipment and the range of performance.

For public spaces, providing an accessible walkway outside the splash zone makes it easier for people who don't want to get wet to use the area.

The placement of the lamp and the nozzle plate must also be coordinated with the floor strapping and the movement path so that the implementation of the installation does not create an irregular surface or full of small and fragile parts.

9–6. Flooring, sliding and accessibility

The fountain floor must be evaluated under actual conditions of use: wet surface, presence of sediment or contamination, foot traffic and, in a water feature project, bare foot contact.

The trade term "anti-slip" is not enough for technical specifications. The test method, test conditions and acceptance criteria should be determined according to the project. The American Access Board guide also explains that the sliding resistance value cannot be accurately interpreted regardless of the measurement method. Source: Access Board floor and ground level guide ^[50]

Important topics in floor details are:

• Flatness of parts and control of level difference;

• The stability of the plates and the absence of loosening;

• The shape and dimensions of the openings according to the users;

• Absence of sharp edges and protruding screws;

• Ability to clean and withstand operating conditions;

• Compatibility of slopes with water collection and accessibility.

The permissible dimensions of openings, slopes and differences in level should be derived from the applicable project criteria. Choosing a fixed number for all projects is not appropriate without specifying the user and design reference.

9–7. Carrying floors, plates and valves

The load of the set exceeds the load of an individual piece. The metal plate, stone, frame, support, connection and substructure must transfer the load continuously.

At the beginning of the design, it should be determined for which times the area will be used:

• Passing and gathering of passers-by;

• Placement of temporary furniture or equipment;

• Passing the cleaning machine;

• The passage of a service or rescue vehicle, if the project requires.

Vehicle passing ability cannot be concluded only from the thickness of a plate or its material. Free opening, wheel load, place of application of load, connections and infrastructure are also decisive.

Also, the installation of a pavilion, stage or temporary structure on the fountain must be in accordance with the load limit and the location of the permitted supports. It is better to clarify these limitations for the complex manager in the site exploitation map.

9–8. Water collection and rainfall management

The collection system must transport the water from the landing site to the final destination. Adequate pipe capacity is useful when water can reach its opening without undesirable water stagnation.

The review chain includes:

Slope of the surface → inlet → channel or chamber → return pipe → tank or permitted disposal route

For each part, the possibility of clogging, cleaning access and the condition of wear and tear should be checked.

Direct rainwater on the area and contaminated runoff should also be determined. It is better to slope around to limit the entry of unrelated runoff into the fountain circuit. Floor washing water, especially with detergent, should not enter the circulating water without checking.

If the system has a reroute between the tank and the drain, the status of the valves and the control logic must be clear. The connection to the disposal network must also be done according to local regulations and with the necessary measures to prevent the return of pollution.

9–9. Calculation example: water collection flow rate

Suppose in an educational plan:

• 18 nozzles are active simultaneously;

• The actual flow rate of each nozzle in this situation is 20 liters per minute;

• The effective area of receiving rain is 180 square meters;

• The assumed rainfall intensity is 60 mm per hour;

• Surface runoff coefficient is considered 1 for this example.

Flow of fountains:

18 x 20 = 360 liters per minute = 6 liters per second

To calculate rain discharge with these units:

Rainfall, liters per second = runoff coefficient × rain intensity, mm/hour × area, square meters ÷ 3600

Therefore:

1 × 60 × 180 ÷ 3600 = 3 liters per second

If, in the design scenario, the fountains remain active during this rainfall and both streams reach a common collection path:

Calculated inlet flow = 6 + 3 = 9 liters per second

This number is the initial discharge of the hypothetical scenario; The size of the pipe does not alone determine the number of floors or the final capacity of the system. Drops, slope, downstream level, possibility of clogging and reliability requirements should be considered separately.

Actual rainfall intensity should also be extracted from site design data and criteria. If the display is stopped in the rain, the condition of the transition and the backwater after the stop should still be seen in the calculations.

9–10. Reservoir and water level change

The tank must accept the change of water volume in different stages of implementation. At start-up, part of the water from the tank enters the pipes, fountains and the return path; After stopping, part of it will come back again.

To determine the volume and levels, at least these conditions should be checked:

• Before launching;

• When the routes are full and the return delay;

• Sustainable implementation of various programs;

• Stopping and draining the water of the routes to the reservoir;

• Compensatory water, overflow and related rainfall conditions.

The geometric volume of the tank is not equal to its usable volume. Low level restriction, space required for proper suction operation, overflow level and volume occupied by components affect useful capacity.

The volume of the tank should be obtained from the water balance in the design modes. A fixed ratio based on floor area or number of nozzles is not a sufficient basis without checking the circuit.

The display circuit and the purification circuit may also have different flow rate and timing; The fact that the fountains are clear alone does not prove that the water circulation is suitable for purification.

9–11. Water quality in the show floor and water play

In a dry bottom fountain, the return water can carry surface contaminants with it. In water games, the contact of users with water is also added to this issue.

The CDC explains that in recirculating water systems, collected water is returned to the tank and requires filtration and disinfection before being reused. The absence of standing water on the surface alone does not prevent the transmission of pollution. Source: Water play and water quality in CDC guide ^[51]

The design should specify water source, usage load, particle removal, disinfection method, monitoring and response to disturbance. Leaf and garbage collection filter is not a substitute for purification and disinfection.

In the CDC operating guide, pre-opening inspection, disinfectant and pH control, surface and tank cleaning, inspection of treatment systems and recording of results are discussed. The project plan should define the acceptable limits and the responsible action when those limits are exceeded. Source: exploitation of water fountains

Chemical amounts, circulation time and purification equipment should be determined in specialized design based on usage and relevant criteria.

9–12. Electricity, light and wet environment conditions

In a dry floor fountain, electrical equipment may be exposed to water, moisture, contamination, and public access at the same time.

The electrical design should specify the installation limits, protection method, connection, power sources, cable routing and the possibility of isolation for service. The IEC 60364-7-702 standard is one of the international references related to the electrical installations of pools and fountains; Its application should be adapted to the project classification and applicable regulations. Source: standard range IEC 60364-7-702 ^[52]

The degree of protection of the enclosure, such as IP68, does not alone confirm the safety of the entire installation. The permitted working conditions of the equipment, connections, electrical protection and the way of installation are also important.

For the lights, it should be determined whether it is allowed to operate without water cover or in a low-water chamber and how the heat dissipation is done. The light and its screen must also be compatible with the defined traffic and contact conditions.

9–13. Repair access and sealing

Equipment that is installed under the floor must have a clear path for inspection, removal and reinstallation.

In the access design, the dimensions and weight of the equipment, opening space for the connection, the possibility of restraining the part and protection of the working area should be considered. A hand-pass valve may not be sufficient to replace the pump.

Valves and removable plates must be placed back in the correct, level and stable position after service. Public access to the underground space and tank should also be controlled.

Sealing should be continuous around pipe and cable penetrations, housing-to-structure connections, and movement joints. Testing it before covering the hidden parts makes it much easier to modify.

Figure note from the source manuscript

Figure 3-9: A photo of the execution before flooring, along with a photo of the same location after completion. The compartments, the return path and the location of the valves should be determined. Suggested caption: "Concealed details should be inspected and recorded before wearing."

9–14. User control and seasonal shutdown

The operation plan should clarify the status of the site in different states: active display, temporary shutdown, non-aquatic use, service and seasonal closure.

After the fountains are turned off, surface water or slickness may remain. Time and condition of space reuse should be determined based on actual drainage performance.

For the cold season, the condition of the remaining water in the nozzles, valves, pipes and containers should be managed according to the design and instructions of the manufacturers. Turning off the electricity alone is not a winter program.

Also, temporary covers should be suitable for the type of traffic and should not disturb the necessary water collection routes. Before restarting, equipment must be inspected, cleaned and water conditions and safeguards verified.

9–15. Project testing and delivery

The final test should check the performance of the floor and the hidden infrastructure in addition to the quality of the display.

Allowable water retention ranges, test conditions, level criteria and other acceptance limits should be specified in the project documents so that deliverables are measurable and traceable.

Figure note from the source manuscript

Figure 4–9: A photograph of a dewatering test and a return path check, or a picture of plate alignment control in a GSO project. Suggested caption: "Delivery of a dry floor fountain includes level assessment, drainage and repair access."

The dry floor fountain shows its true capacity when the urban surface and the facilities below it are designed as a complex. The coordination of architecture, structure, mechanics, electricity and operation provides the possibility of transforming a normal area into a dynamic space that can be used at different times.

In Chapter 10, interactive fountains are explored; By focusing on the way of responding to the presence and behavior of the audience, designing the participation experience and coordinating it with technical limitations and conditions of use.