The evacuated tube is the heart of the Seido line of thermal collectors.  Nearly all (99.999%) of the atmospheric gases, or air, are removed from the glass tube. This has several significant advantages:

• Outstanding insulation. Normally the sun's energy would heat the absorber surface, then heat the surrounding air. This hot air would circulate and transfer heat to the glass surface and be lost. In the Seido evacuated tube, there is essentially no air and therefore no convection. Almost all the heat generated is usable, even in very cold, windy or cloudy conditions. When the absorber surface reaches its maximum stagnation temperature of 477F, the glass tube is safe to touch and handle.  Caution: Do not touch the condenser portion of the heat pipe - it may be very hot.

• Long life.  The absorber selective surface itself is contained entirely within the evacuated space, unlike many other evacuated tube designs. The selective surface will never gather dust or oxidize and will look and perform like new for many years. The vacuum is warrantied for 10 years and is expected to last much longer. The thick borosilicate glass is designed and tested to withstand hail up to 1.38 inches.  

• Convenience. The days of hauling heavy and awkward collectors to the roof are over. Each individual tube is light and can be safely carried to the roof and assembled by one person. The same is true for the header and other components. Warning: become knowledgeable about and always use fall protection equipment. 

• Aesthetics. Customers appreciate the modern high tech look of evacuated tubes. Their high performance allows a small footprint on the roof. Additionally, the round tube is well suited to gathering diffuse radiation which often allows a visually pleasing flush mount, even on non-south roof pitches.