Blinds or covers please for Solar panels.

[Johnny Lee]

Does anyone supply and fit them here ? Radiant s are producing too much heat in summer and water is much too hot damaging system and dangerous.

[kibsolar1999]

you may use the green fabric used for "agriculture shading".
its quite cheap and somewhat UV resistant.
they cut approx 50% of the sunlight.
two layers and you are at approx 75%.
try to use some of hot water for your washing machine.

[Johnny Lee]

Thank You Kibsolar. The client is trying to locate the proper retractable specialist blinds but if all else fails I will make something, Thank You. At 4.00 PM today the water from the shower was 91 C.

[alphamike]

I would like a solution too, am sure I cannot be the only one. Shower is way too hot within a minute or two. I've got a bit used to it, as in turning water off/down. Not so good with guests suffering scalding hot water.

[IPMAN]

are you sure its not the pipework on the roof thats making it hot - I have this system installed and it its hot at first as the pipes are in the open on the roof, after about 30 secs though its fine - i intend to lag the pipes when i get time.

[kibsolar1999]

well, this is a problem for all solar thermal systems which are not temperature controlled.
basically all "local" systems are in this group.

pls also note that from temps above approx 65 degrees you will get heavy lime scaling, due to precipitation (correct word?)
same happens, eg, in kettles.
bad especially for "open systems", but also uncontrolled "closed systems" can be affected.
(eg, the "new" vacuum collectors" from TR)

retractable blinds are usually made for indoors and are usually not UV / wheather- wind protected

a lot of effort for little energy gains.
(average energy needs for DHW, say, 1,5 - 2 , max 3 kWh a day = 550 - 730- 1100 kWh a year)
and potentially a lot of problems
(temps.. either not sufficient ( so, you need a back up.. ) or too high, lime, leaks, glass breaks and so on... )

you may better cancel that rubbish and find other possibilities.

[Laura B]

Kibsolar. I think maybe you mean calcification. With respect.

[kibsolar1999]

laura..
ok, google
At temperatures below 60 ° C significantly less lime precipitates than in warmer water. The hot water temperature should therefore be around 55 ° C.

[Mr Chinnery]

Is this the cold water tap water that is scolding hot?

[Laura B]

Kibsolar. Ah ok. It's a strange use of the word as precipitation, as I understand it, is moisture falling, as in rain snow etc. Obviously it has a wider meaning.

[gates]

With these new high tec solar installations have been a problem from the start . The tubes keep blowing this i know has been happening since they first started 14 years ago to hot water plus the fact is they may if the heat welds under your floor are not good they may blow out . You cant beat the old system here due to the heat . Some times in the winter you need to put on your immersion heater big deal i still have some of my uk immersion heats left last ten years been putting them in now for that long no complaints so hows that for credit

[Johnny Lee]

Thank You for your replies. Yes it is the HOT water that is this hot . Gates it is consistent . It has already damaged seals on system. I am in the process of trying a solution I will run a test next week and keep you posted.

Yes Kibsolar, the more efficient systems are a problem in hot weather. I read on line it is becoming a worldwide problem, . I found even a guy who's system burst after 2 days sun in the North of the UK

I have found proper dedicated roller blinds , but only found them in the States and Africa at present. ( Not expensive).

I will post some reports as soon as I can monitor the problem.

Once again Thank You.

[Johnny Lee]

I promised you an update. I have taken on board Kibsolars comments re. material. Thank You. I have done it such away that nothing is damaged and it can easily be adjusted or removed dependent on weather.

But I will probably need to come up with a more professional method after summer. I have a few ideas on this. But what I have done looks neat and tidy for the moment. Happy to send photos but I don't know how to do it via forum.

There are 2 systems, one for each side of the villa. So for experimental purposes I left one with slightly more radiant uncovered. I am happy to say that after monitoring temp. of water in bathrooms at 4.00 pm for 4 days. I am now getting temperature of 61 C from one side and 55 C from the other.

A massive improvement.

[Mr Chinnery]

Would installing mixer taps be an option.

[Johnny Lee]

All showers and taps there are mixers. But not thermo controlled. You just don't want water over approx 55 C really coming though any tap. Plus the hotter the water the more Limescale is produced. ( Kettle Steam irons etc.)

[kibsolar1999]

Would installing mixer taps be an option.

yes, but you need a good one... not that yoou have to go to the roof every week to adjust the "target temperature"... as lime can become a problem as well.
also, they do not work good in non pressurised systems.

basically you can say... nearly all DHW systems available here are not good. problems everywhere.
starting with the way to heat water, to store, lime., leaks..and only could be solved when people are willing to invest more money for their systems installed in houses in general.
eg, water softeners, better storage tanks, closed loop solar systems .. or... DHW with PV... better positioning of the storage tanks (water management) = to USE the hot water as well, eg, for washing machines and so on.

same applies for other "subjects" as eg, insulation of houses.. then we would not have this long long discussions of which aircon is best... as you may only need one for the whole house...

so, go up in june and cover the solar collectors... and take it off middle of september.

[Keithcaley]

Posted on behalf of Johnny Lee: -

"Damage apparent to virtually new gaskets.
Now problem solved with Sun screen"

see attachments

[Johnny Lee]

Thank You kindly Kieth. Kibsolar , thank you for your tip also. Would you believe this system was too hot in May.

[Mr Chinnery]

Who fitted this system?
I have had the same set up for at least the last 3 to 4 years without any problems whatsoever.

[Johnny Lee]

It would not be ethical to name supplier. It would also cause problems with on going relationship. But this system is in total open sun, no shade whatsoever.

If you research this it is becoming a worldwide issue.

[kibsolar1999]

I have had the same set up for at least the last 3 to 4 years without any problems whatsoever.

well, maybe your system isnt very good... = does not heat properly?

If you research this it is becoming a worldwide issue.

because they are not temperature controlled !!! = stop heating the water at a to be set temperature!

a customer just showed me a price for a "turkish-china system , it was 5400 TL all in, which is, today approx 850 euros.
at alibaba they sell those stuff for 180 - 300 dollar. what do you expect for such a cheap price?
no wonder that, if customer are maybe a bit too price sensitive, this becomes a "worldwide issue"

[Mr Chinnery]

My system works perfectly well, the hot water is more than hot enough.
The reason I changed it 4 years or so ago was because the original system that was about 14 years old and was showing signs of wear ie, solar panels were showing signs of corrosion, the non return valves were having to be changed very regularly and as most people I knew then had to have the hot water tank replaced as it had failed (split) this had not happened to my old system but I thought I was pushing my luck with it.
Also the ‘ hot water season’ from the old system seemed to be getting shorter ie April to September so thought the solar panels were not as efficient.

So I decided to rethink and went for the tube system in which everything was changed on the roof. Never had a problem since and the Hot Water season has expanded by a total of about 3 months one at the beginning and two at the end so March to November. The cost of my system at the time was not much more expensive than having the old replaced with exactly the same that was there. I did however gain two quality stainless steel tanks rather than a plastic cold and ordinary metal hot water tank and although it’s on the roof in full sun does look better/more modern than the old system.

Having looked at the pictures earlier in this post of the system that was problematic it looks to me that it is an older system, although I might be wrong. The general appearance looks to me to be poor quality. The system I had fitted still looks as new.
I am very pleased with it.
This is my experience, others will probably have a different experience.

[Johnny Lee]

It is a new system . Simply too efficient for the position In relation to hours of sunlight and temperature. nothing wrong with company's actual fitting.

My only criticism would be initial survey ? Calculation as per Cyprus hours of sunlight etc. etc.

Even if you used the best quality thermo. shower mixers etc. The temperatures that were being achieved prior to screening would have damaged the system the system. IE The plastic ball cock melted I had to change for metal.