Evacuated tubes are the absorber of the solar water heater. They absorb solar energy converting it into heat for use in water heating. Evacuated tubes have already been used for years in Germany, Canada, China and UK. There are several types of evacuated tubes in use in the solar industry. At Sunlit, we use the "Twin-Glass Tube" technology. This type of tube is chosen for its reliability and better performance.
| Length (nominal) | 1800 mm |
| Outer Tube Diameter | 58 mm |
| Inner Tube Diameter | 47 mm |
| Glass Thickness | 1.6 mm |
| Material | Borosilicate Glass 3.3 |
| Absorptive Coating | Graded CU-N/CU |
| Absorptance | >92% (AM1.5) |
| Emittance | <8% (80oC) |
| Vacuum | P<5x1-3 Pa |
| Stagnation Temperature | >200oC |
| Heat Loss Maximum | <0.8/(m2oC) |
| Strength | 0.8MPa |
| Inner Tank Material | Stainless Steel / Copper |
| Outer Tank Material | Aluminum Stucco |
| Tank Capacity | Customized to Customer Requirement |
| Inlet/Outlet Pipe | Stainless Steel / Brass |
| Tank Welding | Tig Welding / Brazing |
| Filler Material | Stainless Steel / Copper |
| Thermal Insulation | Rock Wool / PUF |
| Heat Retention | 72 hours |
Focusun Energy Systems is a leading designer and manufacturer of Solar Thermal and Solar Photovoltaic Systems.