Solar Collector
Non-pressurized Vacuum Tube Solar Collector
Direct-flow non-pressurized collector for open-loop systems.
- Open-loop designWater flows directly through vacuum tubes
- Low cost & high efficiencyBest value for warm-climate installations
- Simple maintenanceIndividual tube replacement without draining tank
- Lightweight frameEasy roof mounting with standard brackets
| Area | 2.0m² |
|---|---|
| Type | Non-pressurized |
| Coating | AL-N/AL |
| Pressure | 0.05MPa |
Product Introduction
The non-pressurized vacuum tube solar collector is an open-loop thermosiphon system where water flows directly through the inner glass tubes. It offers a simple, reliable, and cost-effective solution for solar water heating in non-freezing climates.
Because the water is heated directly inside the tubes, heat transfer losses are minimized and system efficiency remains high throughout the day. The collector is commonly paired with a non-pressurized storage tank.
This collector family is especially popular in Africa, Southeast Asia, the Middle East, and Latin America where freeze risk is low and budget sensitivity is high.
Main Features
- Direct water flow through 47mm or 58mm vacuum tubes
- No heat exchanger or circulating pump required
- Natural thermosiphon circulation
- Powder-coated steel or aluminum frame options
- Individual tube removable for cleaning or replacement
- Optional electric backup heater interface
Specifications
| Model | Tubes | Tube Diameter | Aperture Area | Daily Output | Tank Pairing |
|---|---|---|---|---|---|
| EP-NP10 | 10 | 58mm | 0.93 m² | 80-100 L | 100-150 L |
| EP-NP15 | 15 | 58mm | 1.39 m² | 120-150 L | 150-200 L |
| EP-NP20 | 20 | 58mm | 1.86 m² | 160-200 L | 200-250 L |
| EP-NP25 | 25 | 58mm | 2.32 m² | 200-250 L | 250-300 L |
Item Details
System Layout
- Collector
- Tubes face south at local latitude tilt.
- Tank
- Non-pressurized tank installed above collector for thermosiphon.
- Auxiliary
- Optional electric element for cloudy-day backup.
Climate Suitability
- Best for
- Tropical and subtropical regions without frost.
- Avoid if
- Ambient temperature drops below 5°C regularly.
- Workaround
- Add drain valve or use heat-pipe collector instead.
Maintenance
- Tube cleaning
- Wipe tubes with soft cloth and clean water twice per year.
- Seal check
- Inspect silicone gaskets every two years.
- Scale prevention
- Use soft water or install a water softener.
Core Application Scenarios
- 01Residential warm-climate hot water
- 02Budget commercial projects
- 03Rural and off-grid installations
- 04Swimming-pool auxiliary heating
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