Climate and environmental conditions

Climate and environmental conditions

Wind, evaporation, heat, frost, dust and seasonal operation

The urban fountain works in a changing environment. Wind, radiation, air temperature, precipitation and environmental pollution can change the form of water, consumption, display quality and life of equipment.

For this reason, a plan that works well in a city or even a site may need to change the height, placement, materials or operation plan in another place.

Climate design should specify the conditions under which the water fountain works with optimal quality, when its output should be limited, and how the equipment is protected during the shutdown period.

15–1. The climate of the region and the actual conditions of the place

Climatic data provide a general picture of the region; But the fountain works in the local conditions of the installation site.

Buildings, trees, walls, difference in height and direction of passages can change the wind and radiation. A fountain in an enclosed yard may behave differently than the same design in an open square.

Three levels of information should be checked in the site study:

WMO climate normals are based on thirty-year periods and are useful for understanding the general pattern. However, averages alone do not specify the boundary conditions required for design. Source: WMO climate norms ^[86]

In the project, the data source, the statistical period, the distance of the station from the place and the limitation of using the information should be recorded.

15–2. Performance conditions and equipment tolerance conditions

Two questions must be answered separately:

Under what conditions is the fountain allowed to run?

What conditions should the structure and equipment endure during the shutdown?

The show may stop during high winds, but the stands, lights, cables and structure are still exposed to wind and rain. Shutting down the pump does not remove the structural strength requirements.

The same separation is also used in the cold of winter. Stopping the show can be part of the program, but water remaining in the tracks and equipment maintenance conditions should be considered separately.

The design documents should specify the range of normal operation, limited mode, shutdown and off-season protected mode.

15–3. Wind and water deformation

Wind can change the path of the jet, the landing place of the drops and the continuity of the water curtain. The result may be reduced readability of the display, wetting of the passageways, or water escaping from the collection area.

The sensitivity of the effects is not the same. Their behavior depends on the height, droplet size, flow continuity, exit angle and duration of presence of water in the air.

The following items should be seen in the wind inspection:

• Frequent directions and effective gusts;

• Place of spectators and public routes;

• The effect of buildings and corners of the area;

• Changing the spray range in different display modes;

• The possibility of reducing the height or removing some effects.

The wind speed recorded at the weather station is not directly equivalent to the wind at the nozzle location without checking the height and measurement conditions.

Figure note from the source manuscript

Figure 1-15: Plan of a fountain with main wind directions, observation points and spray area in both calm and windy conditions. Suggested caption: "Wind can push the actual wetting range beyond the initial display geometry." Limits are derived from project testing or analysis.

15–4. Wind dependent control

Wind control can have several performance levels:

For example, OASE introduces a system that receives anemometer data and gradually reduces the height of the fountain or stops the system. This is a sample product and the appropriate threshold for each project should be determined separately. Source: OASE wind dependent fountain control ^[87]

The location of the anemometer should represent the conditions affecting the fountain. Installing it behind a barrier or at an unrelated point can make the control decision inappropriate.

The return condition is also important. If the system switches between the two states with every small oscillation, the display will become unstable. The appropriate distance between the reduction and return thresholds and the required stability period should be defined in the control design.

15–5. Evaporation and compensation water

Evaporation is dependent on air temperature, humidity, radiation, air movement and characteristics of the water-air contact surface.

In the fountain, in addition to the surface of the pond, jets, drops and wet surfaces can also play a role in exchanging water with air. Therefore, the evaporation estimate of a quiet surface does not necessarily represent the evaporation of the entire display.

In the guide for outdoor water features, EPA suggests water recirculation and proper placement, including the use of shade, as ways to reduce consumption. This guide is not a substitute for the specific calculation of an urban fountain. Source: WaterSense Outdoor Water Features Guide ^[88]

In estimating the consumption, one should differentiate between these items:

• Evaporated water;

• Water removed from the collection area as a result of spraying;

• Scheduled draining and washing;

• leakage;

• Input compensation water.

The flow rate of the pump is not the amount of fresh water consumed.

15–6. Computational example of water surface evaporation

For a simple estimate of horizontal surface evaporation:

Evaporation volume, cubic meter = surface area, square meter × depth of evaporation, mm ÷ 1000

Suppose:

• Free surface of water: 120 square meters;

• Estimated daily evaporation for the same level and conditions: 6 mm.

Then:

Evaporation volume = 120 × 6 ÷ 1000 = 0.72 cubic meters per day

That is 720 liters per day.

The number 6 mm is an educational assumption and is not provided for a specific city or project. The actual rate must be obtained from appropriate data, a valid estimation method or measurement.

Also, this calculation only shows the share of the assumed level. The effect of active effects and other levels should be included in the total estimate.

Multiplying a daily summer rate by all the days of the year is not a good estimate of the annual consumption; Change of season and working hours should be seen.

15–7. water balance; Calculate the actual need for compensation

For a specific period, we can write:

Storage change = compensation water + accepted rain input − evaporation − sprinkler outside the circuit − discharge and washing − leakage

All components must be expressed for a time period and with the same volume unit.

Independent educational example

Suppose for a day:

• Estimated total evaporation of the system: 0.72 cubic meters;

• Spraying outside the circuit: 0.18 cubic meters;

Drainage and washing: 0.10 cubic meters;

• Rain, leakage and storage change: zero.

In this case:

Compensation water = 0.72 + 0.18 + 0.10 = 1 cubic meter per day

If the demonstration pump works for 8 hours a day with a flow rate of 30 cubic meters per hour:

Volume passing through the circuit = 30 × 8 = 240 cubic meters per day

This 240 cubic meters is the volume of repeated passage in the circuit; In the present example, the daily compensation water is one cubic meter.

For actual control of consumption, installation of compensating water meter along with recording of working hours and level change provides very useful information.

Figure note from the source manuscript

Figure 2–15: Water balance diagram with arrows for compensation water, internal circulation, evaporation, spray, and discharge. Suggested subtitle: "Circulating water and consumed water are two different quantities." The sample values ​​should be specified as "educational assumption".

15–8. Heat, radiation and equipment temperature

The air temperature declared for the city is not necessarily the temperature inside the panel or installation chamber. Direct radiation, color and material of the body, ventilation and heat produced by the equipment can change the conditions.

In the design, it should be checked:

• In what environment are the panel and power supply installed;

• How the equipment dissipates its heat;

• Is the ambient or water temperature limit observed;

• Cable, seal and polymer parts are suitable for radiation and location conditions;

• What temperature do the accessible surfaces reach?

The addition of shading or ventilation must be compatible with the degree of protection and installation instructions. Creating an opening in an enclosure, without design, can alter its protection.

Radiation and heat also affect water. CDC guidelines for decorative fountains list temperature, water retention time, sediment, and biofilm as water quality management factors. Source: Management of decorative fountains CDC ^[89]

15–9. Freezing and winter program

Cold can damage remaining water in pipes, valves, nozzles, housings and equipment. Water splashes on public paths may also create slippery conditions.

The winter schedule should clarify the status of each section:

Turning off the power is not a substitute for winterization.

For example, in some of its floating fountain guides, Kasco recommends removing equipment in areas with significant frost. The maintenance method must be derived from the command of the same model. Source: Kasco Floating Fountain Guide ^[90]

The restart condition should also be checked; An increase in air temperature in one hour does not necessarily mean that all roads are de-iced.

15–10. Dust, leaves and environmental pollution

Ingress of particles can increase the cleaning and treatment load, block delicate outlets and reduce the quality of light or material surface.

In dusty places, the choice of equipment should be compatible with the possibility of access and cleaning. A very delicate outlet and an inaccessible enclosure may result in high maintenance costs.

Possible solutions include the following:

• Collecting particles in accessible places;

• Choosing the filter according to the needs of the equipment;

• access to the collector and distribution chambers;

• Reducing the entry of contaminated runoff from the surrounding area;

• Cleaning schedule tailored to dust or leaf fall events.

Filtration should be accompanied by condition monitoring. Filter clogging can alter hydraulic performance; Increasing the power of the pump is not a good answer to a clogged strainer.

15–11. Coastal climate, salt and corrosion

In a coastal environment, only seawater is important. Salt deposition on surfaces, humidity, and wet and dry cycles can also create corrosive conditions.

In the Atmospheric Corrosion Guide, Outokumpu introduces chloride deposition and limited natural washing as effective factors in coastal and urban environments. Source: atmospheric corrosion of stainless steel ^[91]

The selection of materials should be based on the actual environment. The title "stainless steel" alone is not a sufficient specification, and a specific grade does not guarantee the same for all coastal conditions.

The inspection should cover the material of the part, the quality of construction and welding, the grooves that keep pollution, the connection of different metals and the possibility of washing.

Various groups of nozzles, pumps and fittings have been introduced in GSO products; The material specifications and allowable conditions of each model should be confirmed when selecting for the project environment. Source: GSO urban fountain equipment ^[92]

15–12. Rainfall, runoff and flooding

Rain can enter the fountain directly or carry surrounding runoff to it. These two entries must be separated from each other.

Runoff from the path, green space or roof may have different pollution. Using it in the circuit requires checking the source, quality and user requirements.

The design should specify:

• How is direct rain water managed;

• How is the entry of unrelated runoff limited;

• Where does the tank overflow go?

• What is the state of the enclosures and signs against flooding;

• How does the evacuation route work during a power outage?

Collection capacity should be considered for design scenarios. Stopping the show during rain does not eliminate residual water on the track and the risk of backflow downstream.

15–13. Design response to prevailing conditions

The table below shows the initial orientation; Each project may have several statuses at the same time.

This table does not determine the absolute superiority of a type of fountain. For example, lowering the height may reduce the splash, but the display quality should be re-examined.

Figure note from the source manuscript

Figure 3–15: Four conceptual views of a design in wind, sun, dust, and winter shutdown conditions. Suggested subtitle: "Climate design considers different life modes of the project." Concept images should not be attributed to the implemented project.

15–14. Seasonal exploitation program and data recording

A suitable program can have several distinct states instead of one fixed state:

• Normal program;

• low-altitude or low-sprinkling program;

• limited execution at convenient hours;

• temporary stoppage due to environmental conditions;

• seasonal closure and protection;

• Reboot after inspection.

Data recording should help decision making. Information such as make-up water, operating hours, wind stoppage, water temperature, fault and cleaning operations can show how design assumptions differ from reality.

Planned downtime due to environmental conditions should be recorded separately from equipment failure. This breakdown is important to evaluate the actual accessibility of the show and modify the next year's schedule.

Also, reducing the display hours should not disrupt the necessary program for water quality management without review.

15–15. Climate delivery documents and criteria

The design and delivery package should include the following:

All weather conditions may not exist on the day of delivery. In this case, it should be clear which items are supported by evidence and analysis and which tests will be completed in the appropriate period.

Figure note from the source manuscript

Figure 15–4: Photo of seasonal inspection or environmental sensor adjustment in a real GSO project. Suggested subtitle: "Seasonal monitoring and maintenance turns design information into sustainable performance."

The design according to the climate allows better use of the fountain throughout the year. The selection of effects, materials, controls and maintenance programs should be based on the actual conditions of the location so that the quality of the display and the consumption of resources remain manageable.

In chapter 16, preliminary studies and compilation of the description of the fountain project are reviewed; From collecting site information and determining the employer's goals to preparing documents that are the basis of design, estimation and contract.

Environmental studies and design