305 Liters Complete Stainless Steel Solar Water Warmer with 5L Auxiliary Supply Tank
305‑liter full‑stainless‑steel integrated passive solar water warmer comes complete with built‑in 5L auxiliary supply tank (feed tank). It adopts natural thermosyphon gravity circulation without circulation pump. The 5L auxiliary supply tank with internal float‑valve realizes automatic mechanical water refilling for the non‑pressurized main tank, no electric water‑filling controller required. Full stainless‑steel construction delivers outstanding anti‑corrosion performance, well‑suited for household large‑volume domestic hot‑water demand for bathing, laundry and kitchen use. Optional electric auxiliary heating guarantees stable hot‑water output under cloudy‑rainy low‑sunlight conditions。
Working Principle
- High‑efficiency borosilicate evacuated vacuum tubes absorb solar radiation and convert sunlight into heat. Hot‑cold water density difference drives natural thermosyphon passive circulation inside the integrated unit, heating water stored in the 305L main tank without pump or external power consumption。
- The matched 5L stainless‑steel auxiliary supply tank is mounted on top of main tank. Internal float‑ball valve automatically controls water inflow: when main‑tank water level drops, float descends to open inlet valve for automatic refilling; once full, float rises to shut‑off water supply, preventing overflow. It realizes reliable mechanical water make‑up without electronic controller。
- This is non‑pressurized gravity‑type solar unit. Hot‑water flows out by gravity water‑head height difference. Direct connection to high‑pressure municipal tap‑water to main tank is forbidden.
- During insufficient‑sunlight periods, optional built‑in electric heating element heats tank water to secure continuous all‑day domestic hot‑water supply.
Important note: Install on load‑bearing rooftop structure. The 5L auxiliary supply tank must be installed higher than main tank to guarantee gravity refilling function. Pipeline anti‑freeze insulation is mandatory in cold frost‑prone zones. Magnesium sacrificial anode rod is consumable spare‑part and needs regular inspection and replacement. Main tank is non‑pressurized; never connect mains high‑pressure water directly to main tank body。
Core Technical Specifications
‑ Main Tank Capacity: 305L ‑ Auxiliary Supply Tank: 5L, stainless‑steel material, built‑in float‑ball valve for automatic water feeding ‑ Inner Tank Liner: Full SUS304‑2B / SUS316L food‑grade stainless‑steel; replaceable magnesium sacrificial anode rod ‑ Insulation: 50‑55 mm high‑density closed‑cell PU integral foaming, minimize standby heat loss ‑ Working Pressure: Non‑pressurized gravity working condition ‑ Solar Collector: Φ58×1800mm borosilicate glass evacuated vacuum tubes, high‑selective absorbing coating ‑ Circulation Mode: Natural thermosyphon passive circulation, no circulation pump, zero‑power for solar heating ‑ Auxiliary Heating: Optional 2000‑3000W built‑in electric heating element ‑ Outer Casing & Bracket: Full stainless‑steel outer shell, heavy‑duty hot‑dip galvanized anti‑rust rooftop mounting bracket ‑ Typical Service Life: 13‑18 years under standardized routine maintenance ‑ Certifications: CE, ISO9001 available for export shipments
Application Scenarios
‑ 305L large‑capacity for 6‑9‑person big families, multi‑bathroom residential hot‑water usage ‑ Flat & sloped rooftop installation, rural housing, large‑family energy‑saving renovation projects ‑ Areas with unstable tap‑water supply; prefer mechanical auto‑refill without electronic controller ‑ Inland and coastal residential locations
Collectors require minimum 4‑6 hours effective direct sunlight daily. Avoid shading from trees and surrounding buildings. Confirm rooftop load‑bearing capacity before installation.
| Feature | 305L Complete Stainless‑Steel Solar Water Warmer with 5L Auxiliary Supply Tank | Ordinary Non‑Pressurized Solar Heater (without auxiliary tank) | Pre‑heated Copper‑coil Integrated Solar Heater |
|---|---|---|---|
| Water Feeding Mode | 5L auxiliary supply tank, mechanical float‑valve auto refill, no controller | Manual fill / need electronic controller | Need separate feed tank |
| Tank Material | Full stainless‑steel inner & outer casing | Color‑steel outer casing | Stainless‑steel / color‑steel optional |
| Circulation | Passive thermosyphon, no pump | Passive thermosyphon, no pump | Passive thermosyphon, no pump |
| Main‑tank Pressure | Non‑pressurized gravity type | Non‑pressurized gravity type | Non‑pressurized main tank; copper‑coil loop pressurized |
| Best‑fit Scenario | Large‑size family, unstable water‑supply area | Basic household application | Household requiring mains‑pressure shower |
Key Buying Considerations
- Rooftop load‑bearing: Verify roof load‑bearing capacity before full‑unit rooftop installation.
- Auxiliary tank mounting: 5L auxiliary supply tank must be installed above main tank to ensure gravity‑driven auto‑refill function.
- Water‑supply condition: Main tank is non‑pressurized; strictly prohibit direct connection with municipal high‑pressure tap‑water.
- Climate adaption: SUS316L tank material recommended for coastal salt‑spray and high‑hard‑water‑quality zones; apply pipeline anti‑freezing insulation for cold frost‑prone regions.
- Quotation confirmation: Confirm full set including 305L full‑stainless‑steel main tank, 5L auxiliary supply tank, vacuum tubes, heavy‑duty bracket, sealing fittings and optional electric heating.
- OEM support: Custom logo and spare‑part configuration for bulk export orders.
- Export compliance: CE & ISO9001 certification documents available for overseas customs clearance.
Installation & Routine Maintenance
Installation must be finished by professional solar installers. Adjust vacuum‑tube collector tilt angle according to local latitude. Never activate electric heating unless main tank is fully filled with water.
‑ Every 3‑6‑month inspection: Clean dust on vacuum‑tube surface; check float‑valve operation of 5L auxiliary supply tank and pipe joints for leakage. ‑ Every 1‑2‑year professional service: Replace exhausted magnesium sacrificial anode rod; inspect stainless‑steel shell anti‑corrosion condition; check bracket fastening status.
FAQ
Q: What is the function of the 5L auxiliary supply tank?
A: Equipped with internal float‑ball valve, it realizes mechanical automatic water refilling for non‑pressurized main tank. No electronic water‑filling controller is needed. It keeps main tank from running dry even under unstable municipal water supply。
Q: Is the main tank pressurized?
A: No. The 305L main tank is non‑pressurized gravity‑type. Hot‑water outlet pressure depends on gravity water‑head height; do not connect city high‑pressure tap‑water directly to main tank.
Q: What are advantages of complete stainless‑steel construction?
A: Excellent anti‑rust and salt‑spray‑resistant performance. It performs much better than color‑steel shell units in humid and coastal outdoor environment for longer service life.
Final Conclusion
305 Liters Complete Stainless Steel Solar Water Warmer with 5L Auxiliary Supply Tank is large‑capacity all‑in‑one passive solar hot‑water solution for big‑size households. Adopting full stainless‑steel tank construction, it delivers superior anti‑corrosion capability. Matching 5L auxiliary supply tank with float‑valve achieves mechanical automatic water refilling without electronic controller. Natural thermosyphon passive circulation runs without pump, featuring simple‑structured and low‑failure‑rate. Optional electric auxiliary heating ensures hot‑water supply under low‑sunlight weather. Note main tank is non‑pressurized and auxiliary supply tank must be mounted higher than main tank. Professional installation and periodic maintenance support long‑term stable domestic hot‑water output.
