Solar Water Heater
Non-pressurized Solar Water Heater
Economical compact system for tropical regions and budget housing.
- Vacuum TubeBorosilicate glass 3.3
- Tube SizeΦ58mm × 1800mm
- TankSS304, non-pressurized
- Capacity80L – 360L
| Capacity | 80L – 360L |
|---|---|
| Type | Non-pressurized |
| Material | SS304 inner |
| Warranty | 5 years |
Product Introduction
The non-pressurized solar water heater works by natural thermosyphon circulation. The water tank is mounted above the vacuum-tube collector; as the selective coating inside the tubes absorbs solar energy, the water in the tubes warms, becomes lighter and rises naturally into the tank, while cooler water flows back down to the tubes. No pump or electricity is required — circulation is driven purely by the density difference.
Because the system is non-pressurized (open to atmosphere), hot water is delivered by gravity or a small auxiliary feed tank. This keeps the structure simple, low-cost and highly reliable, making it ideal for tropical and subtropical regions where freezing is not a concern.
All-glass vacuum tubes with ALN/AlN-SS/Cu selective coating reach absorptance of 0.93–0.96, while the SS304 tank resists corrosion for a long service life.
Main Features
- Zero running cost: pure thermosyphon circulation, no pump or power needed.
- Simple, robust compact design — easy to install and maintain, with few moving parts.
- High-efficiency all-glass vacuum tubes, absorptance 0.93–0.96, emissivity 0.04–0.06.
- Corrosion-resistant SS304 stainless steel tank for safe potable water.
- Lowest upfront cost — the most economical solar water heating option for homes and hostels.
Specifications
| Model | Absorbing Area (m²) | Tube Dia. (mm) | Tube Length (mm) | Tubes (pcs) | Tank Capacity (L) | Loading 40HQ / 20GP |
|---|---|---|---|---|---|---|
| NPT-80 | 0.64 | 58 | 1800 | 8 | 80 | 210 / 84 |
| NPT-100 | 0.80 | 58 | 1800 | 10 | 100 | 178 / 70 |
| NPT-150 | 1.20 | 58 | 1800 | 15 | 150 | 128 / 51 |
| NPT-200 | 1.60 | 58 | 1800 | 20 | 200 | 98 / 39 |
| NPT-300 | 2.40 | 58 | 1800 | 30 | 300 | 68 / 27 |
| NPT-360 | 2.88 | 58 | 1800 | 36 | 360 | 56 / 22 |
Item Details
Solar Vacuum Tube
- Material
- Borosilicate glass 3.3
- Size (Dia. × Length)
- Φ58mm × 1800mm
- Absorption Coating
- ALN/AlN-SS/Cu selective absorption coating
- Absorptance (α)
- 0.93 – 0.96 (AM1.5)
- Emissivity (ε)
- 0.04 – 0.06 (80 °C ± 5 °C)
Non-pressurized Tank
- Inner Tank Material
- Food-grade SS304 stainless steel
- Outer Tank Material
- Color steel / Stainless steel (optional)
- Insulation Layer
- High-density polyurethane foam
- Heat Retention
- ≥ 72 hours
- Working Pressure
- Atmospheric (0 bar)
Support Frame
- Material
- Galvanized steel / Aluminum alloy (optional)
- Surface Treatment
- Rust-proof, suitable for outdoor installation
- Service Life
- ≥ 15 years
Core Application Scenarios
- 01Tropical and subtropical homes, apartments and dormitories
- 02Rural and budget housing where mains pressure is unavailable
- 03Hostels, small guesthouses and schools with steady hot-water demand
- 04Sunny areas without freezing risk
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