Water-Saving Retrofit Solution for School Trough Toilets
The sensor water-saving system for trough toilets comprises three components: a main controller, curtain-style infrared
Water-Saving Retrofit Solution for School Trough Toilets
1. Overview
Water is the source of all life, sustaining existence on Earth and driving social development. Its importance and irreplaceability are self-evident. China has long faced water scarcity, with a history marked by frequent droughts—over 1,300 major incidents recorded in more than 2,000 years of historical documents. Per capita water resources in China stand at only one-quarter of the global average, with highly uneven distribution leading to an ever-widening supply-demand gap. In recent years, rapid economic growth and increasing urbanization have driven up municipal water consumption. Combined with shortages, pollution, and waste, this has intensified the conflict between supply and demand, posing a serious threat to sustainable urban development. Consequently, water conservation has become a critical priority for society. GIBO’s sensor-activated water-saving products were developed in response to this market demand.
Since 2006, cities such as Tianjin, Dalian, and Harbin have issued water conservation regulations that strictly enforce planned water use and apply surcharges for consumption exceeding allocated quotas. Beijing has also launched pilot programs in select districts, with the Municipal Higher Education Water Conservation Office establishing specific per-student water usage standards covering dormitory, dining, and shower facilities.
2. Objectives of Water-Saving Retrofits in Schools
Educational institutions, enterprises, and public organizations are major water consumers where waste is widespread. In communal bathrooms, shared restrooms, and cafeteria dishwashing areas, running faucets are a common sight. Many users lack water-saving awareness and fail to shut off taps after use. Therefore, strengthening water management within these facilities is critical. Upgrading water equipment with hardware-based solutions is one of the most effective ways to enforce conservation habits. By mandating automatic shutoff, GIBO touchless fixtures reinforce water-saving behavior, help users develop consistent conservation habits, and effectively reduce water consumption.
The infrared sensor flush valve for trench-type urinals is a high-tech, water-saving solution engineered specifically for the usage characteristics of trench-style restrooms. Utilizing infrared technology, it activates automatically when a user approaches and shuts off when unoccupied, ensuring precise control, hygiene, and convenience. The product offers safety, energy efficiency, and significant water savings through a streamlined design with high integration, user-friendly settings, stable performance, and economic durability. It facilitates easy retrofitting for institutional facilities with minimal investment and rapid return on investment, effectively addressing long-standing challenges faced by primary and secondary schools regarding high water bills, inefficient toilet water usage, and poor sanitation conditions.
Field-verified by end users, these trench toilet flush valves achieve an average water-saving rate exceeding 80%. The system activates immediately upon detecting a single motion sensor signal, offering precise delay control and adjustable refill time. To accommodate various school restroom layouts, the sensor probe features universal adjustment capability, ensuring accurate detection limited to the urinal step or squat pan center zone while preventing false triggers. This redesigned product offers high mounting height, superior vandal resistance, and enhanced safety. It effectively resolves common vandalism issues associated with through-beam sensors, making it highly recommended for educational institutions.
Water Consumption Comparison: Various Toilet Flush Systems
III. Implementation and Investment Analysis of Water-Saving Retrofit
(1) Pricing Structure:
In support of national water conservation initiatives, GIBO offers an exclusive educational-sector discount: only ¥1,200 per set. Purchase now to enjoy one year of free repair service from GIBO.
(2) Project Budget:
1. Equipment Investment:
Depending on product specifications, only one unit is required per urinal trough. The optimal supply price per unit is 1200 RMB. A maximum of three units are needed per floor (one for the women’s restroom urinal trough, one for the men’s restroom urinal trough, and one for the men’s restroom urinal), resulting in a maximum investment of 3600 RMB per floor.
2. Auxiliary Materials Input:
Depending on the electrical wiring layout of each restroom, an average of 3–5 meters of cabling is required per unit, with material costs estimated at approximately RMB 30.
3. Labor Costs
Installation of one unit takes approximately 1 hour, with an estimated labor cost of RMB 40.
4. Total Cost per Unit
Equipment: ¥1,200 + Accessories: ¥30 + Installation Labor: ¥40 = ¥1,270 per set
5. Installation Diagram for Trench-Type Water-Saving Device:
IV. Features of the Smart Water-Saving Control System
(1) Operating Principle of the Sensor Water-Saving Device:
The trench-type water-saving device for public restrooms adds a solenoid valve to the inlet pipe of the existing automatic flush tank and installs an infrared sensor on the ceiling at the entrance of the squat pan area. The infrared sensor automatically detects presence; when someone enters, it sends a signal to the electronic controller, which processes the input via its microprocessor and commands the solenoid valve to fill the automatic flush tank for flushing. If no one is detected, the system remains inactive and does not flush. This achieves hands-free operation with automatic management—flushing only when occupied and stopping when empty—for hygienic and water-saving performance.
(2) Key Features of the Sensor Water-Saving Device:
1. Automatic Sensor: Smart management with microcomputer-controlled full automation—flushes more when heavily used, less when lightly used, and not at all when unoccupied.
2. Digital adjustment: Program parameters can be adjusted in seconds, making it suitable for a wide range of applications.
3. High Reliability: Microcomputer control technology with no battery required; the program is never lost under any circumstances. The system is designed to industrial standards, with a service life of over eight years.
4. Suitable for extreme environments: The product operates reliably in both summer heat and winter temperatures as low as -10°C.
5. Safety: Install at a height of 2.4 meters or above to prevent accidental contact and minimize the risk of vandalism.
6. Easy Installation: No concealed in-wall components required; installation takes just 2 hours.
7. High ROI: Achieves 60%–90% water savings, with full investment recovery typically within 1–3 months.
(3) Key Performance Indicators:
1. Input: AC 220V
2. Output: DC 12V/0.5A
3. Maximum detection distance (radius): ≥6 m
4. Detection angle: 120° horizontal × 30° vertical
5. Delayed close time: 0–999 minutes; Fill time: 1–99 minutes
6. Ambient Temperature: 0–45°C
7. Trigger Mode: Continuous Activation (activates continuously when motion is detected within the sensing zone)
5. Key Components of the Sensor Water-Saving Device:
VI. Component Function Overview:
(1) Sensor-Controlled Water-Saving Device
The water-saving controller is primarily used for program settings. It manages the entire system’s power supply and processing based on signals from the infrared curtain sensor, and controls the opening and closing of the solenoid valve.
(2) Infrared Curtain Sensor Overview:
This product is a high-stability curtain-type passive infrared (PIR) detector. Utilizing advanced signal analysis and processing technology, it delivers superior detection performance and false-alarm immunity, with stability ensured by its design. When a person enters the detection zone, the detector automatically sends a signal to the computer controller.
(3) Solenoid Valve
The system is equipped with a high-performance brass solenoid valve featuring a patented maintenance-free cartridge, suitable for various water qualities.
7. Installation Precautions
1. Before installation, flush the inlet pipes to remove debris. When installing each joint, prevent foreign materials such as pipe dope, hemp, or PTFE tape from entering the piping system. Refer to the diagram for the correct method of wrapping PTFE tape.
2. All pipes must be secured with pipe clamps to prevent any movement or vibration;
3. The control box and solenoid valve should be installed at a higher position (at least 2.2 meters above the floor) to prevent tampering and ensure personal safety;
8. Installation Steps
1. Secure the main unit to the wall using expansion screws (installation near the cistern or water inlet is recommended).
2. Inspect the channel and groove layout to determine probe mounting positions, then install the probes;
3. Install the inlet angle stop valve;
4. Install the solenoid valve with the coil oriented vertically upward;
5. Install the drain pipe;
6. Wire according to the bathroom’s power supply layout. For safety, use compliant cable trunking for proper routing, with a minimum installation height of 2.4 m.
7. Connect the solenoid valve to the output terminal of the control box;
8. Connect the probe control cable to the main unit;
9. Connect the power cord to the power input terminal of the control box.
9. Commissioning
1. After confirming that the power supply and water pressure are normal, turn on the power switch. The power indicator and operation indicator will light up, initiating a self-check sequence with a 60-second forced flush (to ensure thorough cleaning upon power restoration after an outage).
2. Observe the fill indicator light and the cistern water level after the light turns off to estimate the time required to refill the cistern to the flush mark. This duration represents the approximate fill time, which should be adjusted as necessary based on site conditions.
3. Set the delay time: 2–5 minutes for squat pans, 0–2 minutes for urinals; set to 0 if the urinal has no cistern
4. Adjust the sensor angle so that the infrared detection zone precisely covers the active area of the urinal trough. If the detection zone is too wide, water will flush when people merely walk past; if it is too narrow, no flush will occur even when a user stands on the urinal step. As site conditions vary, adjustments should be made as appropriate. For example, for a long urinal trough with high traffic, covering approximately 70% of the central section is sufficient, as any detection of presence will trigger a flush.
X. Routine Maintenance
With normal voltage, the trench sensor water-saving device generally requires no maintenance—simply clear debris from the filter every 2–6 months. If issues arise, over 80% are due to the following causes; please check carefully:
1. Check the power supply: Toggle the power switch on the control box several times. If the power indicator light does not illuminate, inspect the power line.
2. Check the water supply: Open the inlet hose valves, ensuring the main water supply valve is fully open. Long-term accumulation of impurities may reduce water flow through the inlet hose; cycle the inlet hose valves several times to flush out any debris.
3. Clean the filter: After a prolonged water outage, the first supply of water (e.g., at the end of school holidays) often carries significant debris from within the pipes;
4. Replace the Pop-up Waste: After 6 months of use, the pop-up waste may fail to seal tightly or stop water flow; replace it as needed.
If the issue persists after thorough inspection, please contact GIBO. Toll-free service hotline: 800-858-1363.
XI. Precautions
1. The sensor water-saving device's main controller, sensor probe, and solenoid valve must not be exposed to rain or water ingress; avoid direct sunlight on the control box.
2. Ensure no moving objects (e.g., curtains, door drapes, clothing) are within the infrared sensor detection zone;
3. The main controller and solenoid valve of the sensor water-saving device must be installed at a height out of reach to prevent electric shock or accidental damage.
Application Examples of Sensor-Activated Water-Saving Toilet Flushers
