SEIDO10----Heat Pipe Solar Vacuum Tube

Flat plate absorber
High efficiency under low ambient temperature due to ultra high vacuum
Fast start-up due to low thermal capacity of working fluid
Low heat losses due to thermal diode effect
No corrosion or scaling problems due to patented thermo-compression sealing technology

Easy installation and maintenance
High system operation pressure resistance and thermal shock resistance
Higher energy through heat transmission by working fluid compared to thermal conduction
Reliable and durable


SEIDO10 is a heat pipe vacuum tube. SEIDO10 heat pipe tubes have smaller dimensions and bigger condensers compared to SEIDO1 and SEIDO5 tubes. Their features and advantages are identical to SEIDO1 tubes but they appear sleeker due to the outer diameter being only 70 mm and their shorter length of 1800 mm. The heat transfer from the absorber to the heat circulation is performed by the heat pipe which is mounted in the absorber. This heat pipe had originally been developed for the thermal control in satellites. Inside the pipe the heat is conducted with high efficiency to its upper end from where it is released to the heat circulation. Although the heat transport medium of the heat pipe is water the heat pipe is a closed system. The pipe is carefully evacuated and charged with a small amount of water before sealing.
Since the heat transfer liquid of the heat circuit does not flow through the collector itself, installation is very simple and an exceptionally trouble-free operation is guaranteed. Even if a collector tube should get damaged the operation of the system will not be interrupted.

Technical data




Heat pipe vacuum tube with flat absorber


Absorber area

0.1 m²


2 .6 k g

Installation tilt angel

15 ~ 90°


Ø70mmx 1800mm

Collect heat pipe

Copper Ø 8mm

Absorber material

Aluminum, 0.6mm

Selective coating

Aluminum nitride Al-N-O selective coating;

Absorptance: a > 0.94; Emittance: e < 0.06

Glass tube material

Borosilicate glass

Thickness: 1.8 mm

Transmittance: 91%


< 10-5 mbar

Min. ambient tem.


Stagnation temp.


Resistance to hail