The evacuated tube as solar heat collector is an amazing piece of technology.  It is said that the evacuated tube for solar heating was invented in Germany and then sold to a Chinese company some 30 years ago.   The tubes are relatively more efficient than flat plate collectors, but they do have some weaknesses.  There are two primary hazards, (1.)  they can be easily broken especially at the end away from the heat pipe.  There is a small tit on that end where the vacuum was drawn that is  susceptible to  breakage.  (2.)  If the tubes are repeatedly subjected to overheating, the vacuum can be damaged which renders them inefficient or worse, inoperable.

If your tube has turned white down near the barium getter, that is a sure sign that the vacuum has high tailed it and the tube is non functional.  Another dead give away is to check the temperature of the glass on all tubes when the sun is shining brightly  Any tube that feels warm to the touch is sleeping because it is sick. It must be replaced if your system is to stay at peak operating performance.

If the collector array has been mounted on your rook, you can check performance by selecting a frosty morning and any tube that is not frosty is a slacker and should be replaced.

For replacement tubes contact nuSun for brand new tubes at a reasonable price.

This entry was posted on Sunday, March 1st, 2009 at 9:28 pm and is filed under Solar Water Heaters, Evacuated Tubes. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.