Features: 1) High heat effectiveness: higher than all-glass evacuated solar collector tube by 15% 2) Heat pipe conduction: successfully prevents the defects of tube breakage and low power output caused by water fouling and deposits or dust and sand 3) Prevents the tube from being easily broken caused by volume expansion when water freezes in the frigid season 4) Low thermal capacity makes the tube start up quickly 5) Energy output within only 2 minutes of sunshine 6) Insulation temperature can reach 250deg;C, average heat efficiency can still be more than 50%; even under -50°C 5) High efficient selective absorptive coatings and vacuum heat insulation technology ensure the tube has higher heat output in cloudy weather and in moist areas, especially in winter 6) Solar collecting plate is sealed inside a high quality borosilicate glass tube with 5 x 10-3pa of vacuum, to stop corrosion; even in moist conditions