Vacuum Tubes and Manifold

GTC vacuum tubes adopt a highly efficient heat transfer vacuum tube with the highest grade copper heat pipe available. This high grade copper prevents impurities from leaching out and clogging up the heat tubes when they operate at high temperatures. Most companies in China use a lower grade copper however; we elected to give you the consumer the highest possible quality system available. The heat tube is located inside the glass-evacuated tube and is completely separate from the manifold system.

Sun energy is transferred through the outer glass tube and is absorbed by the heat pipe, which has aluminum fins that help transfer the heat to a special heat fluid made from deoxygenated water, copper and other metals, found inside the heat pipe. This fluid travels to the copper head of the vacuum tube and the heat is transferred through the copper, then through the manifold case to the heat transfer fluid (propylene glycol). The vacuum tubes are designed to slide into the manifold and are independent of each other so if you loose a vacuum or a tube breaks the other tubes continue to work. Our glass thickness is one of the thickest in the industry and therefore allows a longer lifespan and safer handling characteristics. Each evacuated tube consists of two glass tubes made from extremely strong borosilicate glass one inside the other. The outer tube is transparent, allowing light rays to pass through with minimal reflection. The inner tube is coated with a special selective coating, which features excellent solar radiation absorption and minimal reflection properties. The ends of the two tubes are fused together and the air contained within the space is pumped out or evacuated (your coffee thermos container theory). This vacuum, which allows molecules to move extremely fast also provides insulate properties. Once the evacuated tube absorbs radiation from the sun, it then converts that energy to heat. The inside of the tube may be as hot as 150 degrees Celsius or 302 degrees Fahrenheit where the outside is cool to the touch. This insulate property allows the vacuum tube to perform well even in cold weather when other types of solar products perform poorly becauseof heat loss (flat plate collector - see frequently asked questions #17). You can pick up the glass tube at operating temperature and not feel the extreme heat of the heat pipe. Use caution when doing this because the copper end will be extremely hot and will burn.

Higher Efficiency: The absorbance rate is increased by 14% with remittance reduction of 30-40%.

Higher Heat conduction: Operating conditions were tested to temperatures up to 270°C and as low as -30°C outside air temperature with viable operation.

Higher Stable Vacuum: Our unique technology plus a thicker glass tube, keeps the vacuum stable, which guarantees a longer life of the tube hence the 10 year limited warranty.

The above picture of the vacuum tube shows the tip is silver this indicator lets you know that the tube has a vacuum. In order to maintain the vacuum between the two glass layers, a barium getter is used. During the manufacturing process of the evacuated tube, this getter (see following picture) is exposed to high temperatures which causes the bottom of the evacuated tube to be coated with a pure layer of barium (silver coating). This barium layer actively absorbs any CO, ₂, N₂, O₂, H₂O and H₂ out-gassed from the evacuated tube during storage and operation, thus maintaining the vacuum. The barium layer also provides a clear visual indicator of the vacuum status. If the silver colored barium layer turns white the vacuum is lost. You should replace the tube as soon as possible after you notice this condition. Note: The unit will continue to operate but at a decreased performance level. Replacement tubes can be purchased from this web site.

• Heat collection is very fast. Its efficiency is greater than 10% higher than normal all-glass vacuum tubes.
• No water is in the tube, so it successfully prevents tube breakage or stoppage and low power output caused by scaling and deposits of dust and sand.
• Low thermal capacity makes the tube start up quickly and energy output within 2 minutes under full sunlight.
• High performance selective absorptive coating and vacuum heat insulation technology ensure the tube has high heat efficiency even in cloudy weather or in moist areas, especially during the winter months.
• Solar collector plate is sealed within a high quality borosilicate glass tube with 5 x 10-3 Pa of vacuum to prevent corrosion even in moist conditions.
• The system is reliable and simple.
• Recovery rate is approximately 5 to 6 hours for a standard system.

GTC-58S-ALU Series