Wednesday, March 28, 2012

Panels leaking: I blame myself

I should have fitted one of these much earlier... :(
27 Mar 2012: Oh dear, my earlier problems with the valve and pump have compounded. It's possible that the pump failed because of build up of air in the system due to a leak from the black panels in the sun box. I have noticed that my expectations have been exceeded for temperatures in the Sunbox, having regularly touched 59ÂșC in the box. What I should have done have forecast that such high temperatures could cause thermal expansion if there was a failure of circulation. I have had problems with disappearing liquid ever since the solenoid valve actuator failed to work, it was not sending a signal to the pump, which was therefore not coming on. My assumption that the old pump is not working may be due to it not being able to fight against an airlock, or that it failed after running dry for a while.
  The guys are presently installing the evacuated tubes, and of course, the first thing they set up after the pumping station is an expansion vessel. I noticed this, and thought it was time to fit one to the existing Surya set up.... but having had to put about 8-12 litres of top up liquid into the system, I realised that there must be a leak - and found it eventually.

Odd to say this, but the thermally insulated construction
and the mirror has been 'too successful' and caused a big leak
in the plumbing because I was stupid enough to ignore the
need for an expansion vessel.  
I will go up the ladder for a visual inspection of the leaking (which is at the top and centre location of the sun box) and decide if it is just a hose or a jubilee clip or something worse. It's likely to much safer to ask my scaffolder to reposition the scaffolding after the work is complete with the evacuated tubes. If the black panels have actually burst, then I don't know if it can be replaced. I hope that the evacuated tubes will be effective - it would give me the opportunity to consider the much bigger option of taking down the sunbox altogether.

I also remember meeting David Matthews of the Ground Source Heat Pump Association at Ecobuild 2011. His comment on my system was that I should consider the risk of stagnation - which occurs when the pump fails and the liquid gets too hot. I should have done something about it last summer while rebuilding the external sunbox.

1 comment:

  1. Installing solar panel is indeed a good investment. You do not only save with your electric bills, you also help in conserving energy. This is eco-friendly too and does not cause any pollution.


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