Hot water report from the solar panel please

Babrew


Joined: 15/09/2010
Posts: 486

Message Posted:
06/12/2011 14:21

Its now 2.30pm the sun has been out most of the day but my water is luke warm, can you let me know if your water is around the same temperature.

carian


Joined: 13/03/2009
Posts: 336

Message Posted:
06/12/2011 14:27

Babrew, we were told when we first came to Cyprus that if you needed to wear a jumper or a cardigan that your solar panels wouldn't heat the water sufficiently. I know this is not a scientifically proven fact but seems to be what we've found to be true over the last 9 years.

dippersgirl



Joined: 04/05/2010
Posts: 795

Message Posted:
06/12/2011 14:32

We have the same problem. Our house has a system that is 11 years old. Last year we renovated one of our outbuildings and added a bathroom. Those solar panels and hot water tank are working well and the water is now warm, whereas the old system is not even lukewarm. I don't know why, but either the pipes are all so furred up or the insulation on the hotwater tank has deteriorated. The plumber is coming after christmas to investigate. Will report back and tell you what he said.

Babrew


Joined: 15/09/2010
Posts: 486

Message Posted:
06/12/2011 14:36

ah oh well think I need to explain the situation more then. From memory Im sure that during the winter when the sun is out most of the day my water was hot enough to have a shower before the sun went down. Ive just had a gas heater system installed and Im sure its blocking the solar panel somehow during the day. Yes I do turn the handle systems to off and put the solar panel handle to on, so its not that I am making a mistake.

kiwikid


Joined: 18/08/2008
Posts: 496

Message Posted:
06/12/2011 16:46

We had this problem last year, so I went on the roof and gave them

a really good clean now there is enough hot water in the afternoon

to wash up and shower. It is amazing how dirty they were even though

ther had been rain. I live in an apartment so it was easy enough to get

to the solar panels, maybe a little harder if you have a villa.

LaptaGeezer


Joined: 01/06/2010
Posts: 407

Message Posted:
06/12/2011 17:34

My water used to be lukewarm at best.. then I had the water tank moved and re-plumbed and the water was very hot. Nothing was done to the panels... it was something in the plumbing method from when it was originally installed. Now the water is very hot and plenty warm enough even in the cooler months as long as the sun is shining of course.

Might be worth getting someone to check the plumbing. Is your water very hot in the middle of summer?

jardap


Joined: 08/08/2008
Posts: 318

Message Posted:
06/12/2011 18:58

hi

It could be that the feeder pipe into the hot water tank has an air lock,happened to us last year,

Went from lukewarm to red hot the next day,seems to have worked,now even on a dull day we have hot water.

Babrew


Joined: 15/09/2010
Posts: 486

Message Posted:
06/12/2011 19:03

Message 6. Yes boiling in the summer. Solar panels 7 years old.



Message 5 Ok so I will try and get up on the roof and clean the solar panels with .....................? soapy water? Then wait and see if any different, if not must check the plumbing.



Bit of a coincidence that this has started since the installation of new gas heater.

deputydawg


Joined: 30/03/2010
Posts: 1727

Message Posted:
07/12/2011 10:35

We find that if you have a pump pressurised water supply but choose to switch it on occasionally to fill tanks rather than have it permanently on this can have an affect on the performance and delivery of hot water via solar panels. It seems that the plumbing systems vary greatly throughout TRNC and what is good methods for one system is not necessarily universal.

MarkVPiazza


Joined: 14/08/2008
Posts: 530

Message Posted:
07/12/2011 11:04

Up to the time we left Cyprus last week, on sunny days our water was very hot, needed the mixer on about the halfway mark.



Are your panels facing south at 45 degrees?, when you look out I can not believe how many are facing east, or sometimes north !!!

deputydawg


Joined: 30/03/2010
Posts: 1727

Message Posted:
07/12/2011 16:31

Mark, a very valid observation regarding the facing of the panels. There must be many factors. For example our tanks are within the building rather than on the roof so heat is retained by central heating and the adjacent chimney breast when we use a log burner. Altitude too must cause variation of ambient temperatures and the number of hours that the sun is directly upon panels.

kibsolar


Joined: 14/09/2008
Posts: 552

Message Posted:
07/12/2011 20:17

Hi, we are not in this kind of "local systems", we do only professional systems for domestic/central heating/pool heating ( and or combined) systems bigger then 10m²... but follow this directions to squeeze out as much as possible:

1.best results of course when collectors face south, 2. make sure that they are "black", a new paint helps sometimes a lot, 3. Blocked pipes (lime) might be a problem 4. now its getting a bit complicated: hot water is "lighter" (lower densitiy) then cold water. The cold water flows into the bottom of the collector (this is the "return flow"), the warmer water leaves the top of the collector into a “riser pipe” (correct word?) . It is important that this flow is “easy” (as it is not “forced” = pumped) and will not be interrupted.

kibsolar


Joined: 14/09/2008
Posts: 552

Message Posted:
07/12/2011 20:18

For that 4a, the hot water tanks inlet must be significant higher as the top outlet of the collectors, 4b, towards the hot water storage, a "steady upgoing" must be achieved, not “up-down-up”( often happens with plastic piping), same applies for the cold water pipe. 4c, the riser pipe should not be too long, 2 meters as a max and MUST be insulated, otherwise the warm water may cool down and flow stops. 5, usually two collectors are used: so the above mentioned “easy flow” also must be achieved inside the collector. They have to be installed slightly as a V (take two pieces of paper to see what I mean) to make sure that the warm water can leave the collector and does not get stuck in one of the corners.

kibsolar


Joined: 14/09/2008
Posts: 552

Message Posted:
07/12/2011 20:19

To achieve this properly, you most probably have to disconnect the collectors from the cold water connection , close them and push the two collector closer together. Then you use a T-junction and reconnect the two collectors separately to the two outside corners, which are now “lower” as the top. This will also make sure that “the whole surface” of the collector is used. One of the problems of this “ cold water through the middle in- warm water though the middle out” connections is, that not the complete surface of the collector is used for hot water production as water always flows the “shortest way” through the collector.

I told 3 dozens plumbers a hundred times.. they do not care.. So, keep it, print it, the last time I posted these hints was 3 years ago.