Are you all pleased with your solar panels for hot water heating

John T Carroll · 03-10-2014 4:17pm

josip wrote: »

Ah, but that changes everything.
In your first post you said 2 toddlers but now we find out they're both girls
In my limited experience, hot water consumption for females is higher than for males and this will halve shorten your payback timeframe.

The savings that I calculated above are based on utilising the full output of 1300 Kwh/Annum ( 30 E.tubes), so even if the hot water consumption increases dramatically then I cant really see any improvement in payback time. However you can now get E.Tube array manifolds to which you can simply "plug in/on" extra tubes as required, the incremental cost of this will be
relatively low as you will already have installed the main system, this will then certainly shorten your payback time.

josip · 03-10-2014 4:48pm

John T Carroll wrote: »

The savings that I calculated above are based on utilising the full output of 1300 Kwh/Annum ( 30 E.tubes), so even if the hot water consumption increases dramatically then I cant really see any improvement in payback time. However you can now get E.Tube array manifolds to which you can simply "plug in/on" extra tubes as required, the incremental cost of this will be
relatively low as you will already have installed the main system, this will then certainly shorten your payback time.

Is plugging in the extra tubes something a householder could do or would an installer be needed?

Does the cylinder size have to be dimensioned according to the number of tubes to maximise the benefit?

John T Carroll · 03-10-2014 9:02pm

josip wrote: »

Is plugging in the extra tubes something a householder could do or would an installer be needed?

Does the cylinder size have to be dimensioned according to the number of tubes to maximise the benefit?

I'd say it would be prudent to get an installer for two reasons: safety, as the tubes will normally be roof mounted and the water/glycol mixture may need topping up depending on the type of E.Tube fitted.

The cylinder size and solar coil area would also need to be sized correctly on initial installation.

John T Carroll · 05-10-2014 12:59pm

josip wrote: »

Ah, but that changes everything.
In your first post you said 2 toddlers but now we find out they're both girls
In my limited experience, hot water consumption for females is higher than for males and this will halve shorten your payback timeframe.

If one can start off with young children using a shower with a flowrate of 5 to 6 LPM rather than the "power" shower of, say 10 to 15 LPM then they will get used to that, its much harder to downsize without having a revolution on your hands.

tipperary · 17-10-2014 8:29pm

ammc wrote: »

Can someone advise me regarding a device for data collection. I have 30 Kingspan evacuated tubes (DF100) connected to a RESOL BS/4 v2 Controller. I can view the temp of tubes and the temp at bottom and top of cylinder on the controller. What would be the best device for recording data to view long term trends that I could connect to my system.

Hi, one of these will give you what you need. You can view data over a day/week/month or custom time range, gives a great insight into how your system functions (todays output attached).
After getting one I ended up changing my controller to one of these units. It's a solar controller that also controls the immersion. I switched to nightsaver power also. I previously ran the boiler to bring the cylinder up to temp, but this wasn't using the boiler very efficiently as the boiler was almost always coming on just to heat the water (we don't turn the heating on very often due to stove and well insulated house). The immersion controller paid for itself in less than a year:D.

Qualitymark · 18-10-2014 8:09am

I wonder if the large and set-to-increase water prices will hit the sale and use of solar hot water panels.

18-10-2014 10:43am

Qualitymark wrote: »

I wonder if the large and set-to-increase water prices will hit the sale and use of solar hot water panels.

I very much doubt it, most solar systems are closed loops so "consume" no water as such.

If anything it will make them more useful as people would waste less hot water so the cylinder would be able to get hotter as less water is drained from it.

The solar heated water is less likely to run out if people are using less.

daved1975 · 21-10-2014 10:45pm

Hi. I am thinking of getting solar panels. I have a bungalow in wexford. Any advice on types and a reliable company to get them from

StaroftheSea · 15-11-2014 10:32pm

Hi,
We are building a new house and are unsure as to go for thermodynamic panels or kingspan Solar panels for domestic hot water. As far as I know the thermodynamic panels heat 100% of DHW requirements, while the Solar panels only provide a proportion of it. Given that they are both coming in at a similar installation cost, why would one go for the kingspan instead of the thermodynamic?

Thanks,

freddyuk · 16-11-2014 7:04am

Because solar thermal systems only have a tiny power drain from a pump (25+ watts) which runs for short bursts thus is basically "free" once installed. Occasional fluid replacement is recommended. A Thermodynamic system requires constant power to run the heat pump (800+ watts??) to make it work thus is effected by the rising cost of electricity over the long term.
You need to calculate the benefit of using the immersion to top up solar thermal (or standard boiler) which may be already installed and consider the payback times/ replacement costs. It is easy to calculate the cost of heating with an immersion based on time/volume so how many cylinders of hot water can you get for the cost of installing and running and maintaining a heat pump (thermodynamic) system.
Replacing a solar thermal pump is easy and cheap if ever required. Replacing the tubes (which are recommended over flat plate) is also very cheap although I would not expect to have to do this for many years.
Replacing a thermodynamic unit would be much more expensive and their service life is not known.
There are other makes/brands of solar thermal and it is how they are installed and serviced not where you get them from which is vitally important for long term, trouble free service.

StaroftheSea · 16-11-2014 9:30pm

Thanks for that Freddy, we are still at a loss to know which to go for. From reading other forums on solar panels it seems to me that they really are not any more cost effective than an oil burner for heating hot water when you take into account the installation costs and servicing etc. . It seems the only reason people are installing them (when you cut through the sales pitches) is simply because they have to because of the new regulations. . . That's 5 grand that could have been put towards something that would actually benefit the house rather paying lip service to the regulations. . .

quentingargan · 17-11-2014 12:37am

StaroftheSea wrote: »

Thanks for that Freddy, we are still at a loss to know which to go for. From reading other forums on solar panels it seems to me that they really are not any more cost effective than an oil burner for heating hot water when you take into account the installation costs and servicing etc. . It seems the only reason people are installing them (when you cut through the sales pitches) is simply because they have to because of the new regulations. . . That's 5 grand that could have been put towards something that would actually benefit the house rather paying lip service to the regulations. . .

It really depends on your hot water use in the summer time. Some people don't use a lot of hot water over the summer, and would be better off using solar PV to meet the regulations in Part L. Especially on larger one-off houses where solar thermal starts to get over-sized. The hardware for a PV system can be as little as 2 grand and requires no maintenance. But other people use heaps of hot water and solar thermal might then stack.

Kingdom · 20-11-2014 12:05pm

Sorry for bumping the thread, esp with just a personal query. I had put out feelers on another forum re solar panels (I'm quite ignorant about it all - not intentionally) and someone whose opinion I'd respect greatly told me to look at Solar Collectors, rather than Solar Panels, for a couple of reasons.

I'm moving into a relatively new house in Dublin (1975 build) with relatively good insulation in attic and windows. It is an oil heated system though, and I know from past experience that Oil isn't cheap, and possibly is going to become more expensive.

I've 3 kids, with a 4th on the way. I've seen some prices quoted online for panelling that goes into the ten thousand figures, and I just don't have the scope for that kind of investment right now, but possibly will in 10 years or so, when I'll need to renovate, or extend anyway.
Ideally a solar energy system that heats water and radiators would be the goal, but a short-term system to heat water would be very welcome, provided it's affordable.
Has anyone got any recommendations, or suggestions?
Any help appreciated, and apologies for hijacking the thread.

josip · 20-11-2014 12:55pm

Kingdom wrote: »

Sorry for bumping the thread, esp with just a personal query. I had put out feelers on another forum re solar panels (I'm quite ignorant about it all - not intentionally) and someone whose opinion I'd respect greatly told me to look at Solar Collectors, rather than Solar Panels, for a couple of reasons.

I'm moving into a relatively new house in Dublin (1975 build) with relatively good insulation in attic and windows. It is an oil heated system though, and I know from past experience that Oil isn't cheap, and possibly is going to become more expensive.

I've 3 kids, with a 4th on the way. I've seen some prices quoted online for panelling that goes into the ten thousand figures, and I just don't have the scope for that kind of investment right now, but possibly will in 10 years or so, when I'll need to renovate, or extend anyway.
Ideally a solar energy system that heats water and radiators would be the goal, but a short-term system to heat water would be very welcome, provided it's affordable.
Has anyone got any recommendations, or suggestions?
Any help appreciated, and apologies for hijacking the thread.

I think you'll have to give up on the idea of heating water and rads. The solar energy just isn't there to do it in the winter when you need it for the rads.

If you over dimension your system to try to get something useful from it Nov - Feb, it'll cost a lot and cause problems in the summer when you'll need to dump all the surplus heat somewhere.

One area for tweaking is the angle of inclination of the tubes/panels. Most are roof mounted and are subject to the 35 deg slope of the roof. Which means they are most efficient during the summer months, when they don't actually need to be most efficient.

A neighbour of ours has mounted theirs at ground level, 15-20 degrees off the vertical so that they are optimised for the winter sun azimut and they still get enough in the summer.

Jakey Rolling · 25-12-2014 9:36pm

30 Tube parabolic array here in South Tipp - heated 300 litre tank to 45deg today, plenty enough for a shower and all the washing up.

Well pleased with this, but have concerns that it is oversized in the summer, resulting in lots of stagnation with the tubes reaching 200C.

championc · 25-12-2014 9:45pm

What was your systems' temperature this morning ? i assume your heating system is heating the tank too so maybe it only rose from 43 deg !!

Jakey Rolling · 26-12-2014 8:15pm

championc wrote: »

What was your systems' temperature this morning ? i assume your heating system is heating the tank too so maybe it only rose from 43 deg !!

Mid tank sensor was down to 24c after morning showers. Heated up from there during the day. Approx 4kwh to heat 150 litres by 20C.

championc · 26-12-2014 8:50pm

OK. But i'm sure you didn't use 300 litres for showers. Maybe John Carroll would be better able to tell you but from experience, you'd need a few consecutive days of sunshine, with little usage, to top out the system

John T Carroll · 27-12-2014 3:02pm

championc wrote: »

OK. But i'm sure you didn't use 300 litres for showers. Maybe John Carroll would be better able to tell you but from experience, you'd need a few consecutive days of sunshine, with little usage, to top out the system

Its interesting to see the 30 Tube Parabolic Tube output above of 3.49 Kwh, I have seen my own system (3.84 M2 F.Plate) producing unexpectedly high outputs on sunny days in Nov/Dec for the past 3 years, (see below). I really cant think of any logical reason for this, maybe its because the sun spends its brief daily sojourn mainly in the South?.

I have used your very useful live data because you also have a 30 E.Tube (Non parabolic Array). A parabolic addition may substantially enhance the output of a 30 tube array.

I have used your own link, below, and readings for the 24th Dec. for a number of reasons, one is that the whole of your cylinder on that day is at the same starting temperature of 9C,it is quite easy then to calculate the energy required to raise it to its final temperature of 20C. The other reason is that the Solar Radiation for Dublin on the 24th was 300 joules/cm2 (0.834 Kwh/M2) which is very close to the Solar Radiation of 308 joules/cm2 (0.856 Kwh/M2) for Gurteen (Roscrea?) on the 25th Dec.

By calculation, your system produced 1.92 Kwh ((180*(14-9)/860))+((125*(20-14)/860))on the 24th. This is substantially less than the parabolic array above but one must bear in mind that even though the apparent solar radiation available was practically the same, local conditions, even a few miles apart, can give quite different results, not to mind Dublin vs Tipperary. Incidentally, I assumed in your case that there was little or no hotwater draw off during the morning/afternoon period, if there was some draw off,then the production was obviously more.

https://xively.com/feeds/1928576781/?from_cosm=true (Open this in Google Chrome or similar)

On the 24th Dec my system made a measured 1.94 Kwh from a Roches Point Solar Radiation of 401 joules/cm2(1.11 Kwh/M2). This equates to an apparent system efficiency of (1.94/(1.11*3.84)) or 45.51%, my annualised system efficiency is around 25%, I have seen the apparent efficiency as high as 55% on occasions in the past 3 years during Nov./Dec.

Evacuated Tube suppliers mostly seem to use an annualised system efficiency of 55%, they use this efficiency when calculating the SolarArray Area, personally I think that the efficiency is nearer 40% to 45%, they also dont take cylinder losses which can amount to 700 to 1000 Kwh into account when calculating the array area required, of course this applies to F.Plates as well. Again, just personally, I think most arrays are quite undersized, of course this gives an enhanced system efficiency, reduces the stagnation days and has lower Capital/Installation costs.

John

championc · 27-12-2014 11:13pm

So from Jakey's system, how many degrees could the whole of 300 litres have been raised on the 25th ? So if the whole tank was at 24 deg, could the whole 300 litres have been increased to 45 deg ?

Jakey Rolling · 27-12-2014 11:34pm

championc wrote: »

So from Jakey's system, how many degrees could the whole of 300 litres have been raised on the 25th ? So if the whole tank was at 24 deg, could the whole 300 litres have been increased to 45 deg ?

Sensor is at mid tank level, hence why I assumed 150 litres in my ballpark calculation.

Suits me that I didn't have to use oil to heat the tank for evening use on near the shortest day of the year. Concerns remain over excessive stagnation in summer.

John T Carroll · 28-12-2014 6:06pm

championc wrote: »

So from Jakey's system, how many degrees could the whole of 300 litres have been raised on the 25th ? So if the whole tank was at 24 deg, could the whole 300 litres have been increased to 45 deg ?

As long as the upper150 Litres of the cylinder remained above 45C then the solar system would only heat the bottom 150 Litres. To heat the whole 300 litres from 24C to 45C would have required Solar Radiation of 1145 joules/cm2 based on your system efficiency of 71.29% on 24th Dec.. To heat 150 Litres from 24C to 45C required Solar Radiation of 572 joules/cm2 again based on your system. The highest December Roches Point Solar Radiation that I have recorded over the past four years was 519 joules/cm2 in 2013. So there is no way, in my opinion, that one could heat 300 Litres from 24C to 45C and nobody has claimed that they could. Raising 150 Litres from 24C to 45C was/is certainly feasible in my opinion and because of the parabolic 30 tube array probably did not require the theoretical 572 joules/cm2. It is still an outstanding performance though from any system.

Bscan86 · 17-03-2015 3:58pm

Hi,
I was talking to a lecturer on energy efficiency and he maintains that it takes over 10 years to pay back. Does anyone else know is this accurate and how much money do they actually save????

17-03-2015 7:13pm

Bscan86 wrote: »

Hi,
I was talking to a lecturer on energy efficiency and he maintains that it takes over 10 years to pay back. Does anyone else know is this accurate and how much money do they actually save????

It really depends on how much you pay for the system in the first place, for example a home made set of collectors made from junk will return in less than a year while a custom made system using specialist equipment may never pay back. The other variable to factor in is the cost of the fuel the solar is supposed to displace.

championc · 17-03-2015 9:12pm

I paid for €5k for my system a few years ago. I monitor my bills for gas and I went from nearly 6 units per day to about 4. My usage will lead to a payback in about 9 years at current prices

lazeedaisy · 17-03-2015 9:20pm

Bscan86 wrote: »

Hi,
I was talking to a lecturer on energy efficiency and he maintains that it takes over 10 years to pay back. Does anyone else know is this accurate and how much money do they actually save????

I had a friend who said the same, for a retro fit

We put them in a new house, it's a passive house, and in 18 months it's cost us 300 in oil, and our elec. bills are very low.

We have 5 panels, and the weather in the last 4 or 5 days has been the worst I have ever seen, very little sun as opposed to 1 week ago the heat was coming in at 58degrees,

We have a stove, and I put a large kettle on it every evening which is used to wash the dishes, I am mindful if there has not been much sun, and work around it. Have not needed to turn the oil on to heat water yet this year,

josip · 18-03-2015 12:40am

We paid €3300 for our system 4 years ago.
Payback time will be around 11 years.
But each time maintainence is needed, eg. air in the fluid, that gets pushed back further.
Pretty much as we expected apart from the maintainence

dr.fuzzenstein · 16-04-2015 8:50am

Hi, I don't have a solar system yet, but can you tell me what you think about this:

http://www.ravensbergersolar.de/solarkollektoren/roehrenkollektoren/8/ravensberger-high-energy-3000-30-roehren-bafa-foerderfaehig

How good/bad can it be at that price, considering the average Irish price is the same but with an extra 0 at the end?

16-04-2015 9:03am

dr.fuzzenstein wrote: »

Hi, I don't have a solar system yet, but can you tell me what you think about this:

http://www.ravensbergersolar.de/solarkollektoren/roehrenkollektoren/8/ravensberger-high-energy-3000-30-roehren-bafa-foerderfaehig

How good/bad can it be at that price, considering the average Irish price is the same but with an extra 0 at the end?

At first glance they look similar to the ones that Navitron sell, as for the missing zero, this is a DIY install and you still have to buy all the mountings, plumbing, pumps and controller.

dr.fuzzenstein · 16-04-2015 9:12am

Deleted User wrote: »

At first glance they look similar to the ones that Navitron sell, as for the missing zero, this is a DIY install and you still have to buy all the mountings, plumbing, pumps and controller.

Makes sense, I'll check it out. I think they have all that stuff too.
Is there a handy guide or suggested reading for installing one of those?
I do know Navitron, for obvious reasons right now is better to buy on a € website, rather than a £ website.

dvdman1 · 16-04-2015 9:18am

Solar panels need maintance and can get damaged in high winds..if their on the house for years what do you think the chances of damage even vandalusm are?
They seem unviable compared to solid fuel substituting oil/gas

16-04-2015 9:23am

dvdman1 wrote: »

Solar panels need maintance and can get damaged in high winds..if their on the house for years what do you think the chances of damage even vandalusm are?
They seem unviable compared to solid fuel substituting oil/gas

Depends on the location and the standard of the installation, well installed panels shouldn't be affected by high wind. My panels have only been up since last Autumn so too early to tell about the quality of the fitting, as for vandalism, my football mad son is the biggest risk (he's been warned!).
Their running costs are far lower than fossil fuels, all you have are the pumps and on some systems are completely passive.

SpaceTime · 16-04-2015 9:28am

How often do they need to be cleaned? Our roof is very high and they'd be quite inaccessible. It'd be handy if you could get self cleaning panels.

Qualitymark · 16-04-2015 11:43am

SpaceTime wrote: »

How often do they need to be cleaned? Our roof is very high and they'd be quite inaccessible. It'd be handy if you could get self cleaning panels.

They don't have to be on the roof; I've seen them on garage rooves.

josip · 16-04-2015 11:54am

SpaceTime wrote: »

How often do they need to be cleaned? Our roof is very high and they'd be quite inaccessible. It'd be handy if you could get self cleaning panels.

Depends on their location and installation angle.
Most of the ordinary atmospheric dust will get blown off/washed off over time in my experience.
If you have trees nearby then the sap from those can build up and should take steps to clean that off, the same as you would a car.
I haven't measured but the amount of dust/dirt I clean off them is almost the same regardless of whether it's 3 months or 2 years between cleanings.
And the amount of it wouldn't affect them by more than 10-15% in my layman's opinion

Palmach · 16-04-2015 1:07pm

Deleted User wrote: »

some systems are completely passive.

When you say passive do you mean no electricity required? I am interested in installing panels so would like to know. Thanks.

John T Carroll · 16-04-2015 2:07pm

josip wrote: »

Depends on their location and installation angle.
Most of the ordinary atmospheric dust will get blown off/washed off over time in my experience.
If you have trees nearby then the sap from those can build up and should take steps to clean that off, the same as you would a car.
I haven't measured but the amount of dust/dirt I clean off them is almost the same regardless of whether it's 3 months or 2 years between cleanings.
And the amount of it wouldn't affect them by more than 10-15% in my layman's opinion

Have no real problems with dust/dirt but once or twice a year either a starling or a blackbird decides to use just one (always the same one) of my panels as a toilet, luckily I have a velux window in my converted attic and I have a hose connected to the mains water, so I just throw a few buckets of sudsy water over the panels and wash them off with the hose, a shotgun might provide a more permanent solution.

dr.fuzzenstein · 16-04-2015 2:11pm

John T Carroll wrote: »

Have no real problems with dust/dirt but once or twice a year either a starling or a blackbird decides to use just one (always the same one) of my panels as a toilet, luckily I have a velux window in my converted attic and I have a hose connected to the mains water, so I just throw a few buckets of sudsy water over the panels and wash them off with the hose, a shotgun might provide a more permanent solution.

I don't think a shotgun is a recommended method for cleaning solar panels.

SpaceTime · 16-04-2015 2:32pm

dr.fuzzenstein wrote: »

I don't think a shotgun is a recommended method for cleaning solar panels.

That's why you shouldn't read Texan eco-heating websites!

John T Carroll · 16-04-2015 2:36pm

dr.fuzzenstein wrote: »

I don't think a shotgun is a recommended method for cleaning solar panels.

No, but its generally lethal when discharged at a small bird from a distance of six feet and should also remove any heavy deposits from the panel.....OK, I promise not to try it.

16-04-2015 6:15pm

Palmach wrote: »

When you say passive do you mean no electricity required? I am interested in installing panels so would like to know. Thanks.

Yes, basically if you have the tank located such that the top of the panel is level with the top of the tank and likewise the bottom is level between the tank and the panel.

The system will work purely on the fact that hot water rises and the heat will "lift" the heated water into the tank drawing cold in behind it.

It works well on flat panels (never heard of anyone using this method with tubes).

josip · 17-04-2015 11:11am

Deleted User wrote: »

Yes, basically if you have the tank located such that the top of the panel is level with the top of the tank and likewise the bottom is level between the tank and the panel.

The system will work purely on the fact that hot water rises and the heat will "lift" the heated water into the tank drawing cold in behind it.

It works well on flat panels (never heard of anyone using this method with tubes).

Since the vast majority of tubes are roof mounted, and the majority of attic water tanks are situated closer to attic floor level, a pump is needed.

These are very common in southern Europe and elsewhere and are a much cheaper solution relying on water convection

dr.fuzzenstein · 17-04-2015 11:55am

Deleted User wrote: »

Yes, basically if you have the tank located such that the top of the panel is level with the top of the tank and likewise the bottom is level between the tank and the panel.

The system will work purely on the fact that hot water rises and the heat will "lift" the heated water into the tank drawing cold in behind it.

It works well on flat panels (never heard of anyone using this method with tubes).

Speaking of panel and tank location, I'm in a bit of a pickle.
My hot water tank is in the middle of a fairly long house, but the solar panels will have to go on the south gable end for ease of installation and aesthetic reasons, otherwise I would have to make them south facing on an east or west facing roof and that would just look horrible and ruin the roofline of the house.
I'm not quite sure about the exact distance, but more than 20 meters in any case.
Question:
What sort of distance from panel to tank is too far? Can I make up for it with using better insulation round the pipe? Will I need an uprated pump? Will Darth Vader be in the new Star Wars movie? Any answer appreciated!

josip · 17-04-2015 1:41pm

dr.fuzzenstein wrote: »

Speaking of panel and tank location, I'm in a bit of a pickle.
My hot water tank is in the middle of a fairly long house, but the solar panels will have to go on the south gable end for ease of installation and aesthetic reasons, otherwise I would have to make them south facing on an east or west facing roof and that would just look horrible and ruin the roofline of the house.
I'm not quite sure about the exact distance, but more than 20 meters in any case.
Question:
What sort of distance from panel to tank is too far? Can I make up for it with using better insulation round the pipe? Will I need an uprated pump? Will Darth Vader be in the new Star Wars movie? Any answer appreciated!

I'm not sure about 20m but we had the opposite, related, problem originally.
Our panels were only 1-2m from the water cylinder with the pump sitting between them. We didn't have a heat dump.
When we went away for the first summer holidays, the panels got to setback temp (around 220 deg I think) and although the fluid wasn't circulating, the heat travelled down the pipe by conduction and burnt out the pump according to our installer.
He then put in an extra 10m of piping to prevent this happening in the future. It hasn't and there hasn't been a noticeable degradation in performance.
So you'd definitely be ok with 10m. Can't say for 20m.
It is rumoured that Darth will make a cameo appearance

a postere · 17-04-2015 1:43pm

sinnerboy wrote: »

I'll sticky this awhile and add

Please indicate

cost
year of installation
m2 area
orientation
flat plate or tubes
cylinder size
summer heat dump strategy ( if any )

Reminder - no trade / company names please

.

I'd love to see money saved by going solar added to this list

freddyuk · 17-04-2015 3:08pm

dr.fuzzenstein wrote: »

Speaking of panel and tank location, I'm in a bit of a pickle.
My hot water tank is in the middle of a fairly long house, but the solar panels will have to go on the south gable end for ease of installation and aesthetic reasons, otherwise I would have to make them south facing on an east or west facing roof and that would just look horrible and ruin the roofline of the house.
I'm not quite sure about the exact distance, but more than 20 meters in any case.
Question:
What sort of distance from panel to tank is too far? Can I make up for it with using better insulation round the pipe? Will I need an uprated pump? Will Darth Vader be in the new Star Wars movie? Any answer appreciated!

You could have East/West installation? Perfectly acceptable method.
20 metres is no problem at all.

freddyuk · 17-04-2015 3:14pm

josip wrote: »

I'm not sure about 20m but we had the opposite, related, problem originally.
Our panels were only 1-2m from the water cylinder with the pump sitting between them. We didn't have a heat dump.
When we went away for the first summer holidays, the panels got to setback temp (around 220 deg I think) and although the fluid wasn't circulating, the heat travelled down the pipe by conduction and burnt out the pump according to our installer.
He then put in an extra 10m of piping to prevent this happening in the future. It hasn't and there hasn't been a noticeable degradation in performance.
So you'd definitely be ok with 10m. Can't say for 20m.
It is rumoured that Darth will make a cameo appearance

There has been no degradation in performance because adding 10m of pipe is not going to reduce the heat of the fluid! If the system let's go the water turns to steam and travels all the way to your pump and expansion vessel. You are risking another disaster without a proper bypass. However the plumber will have to pay I guess.:rolleyes:

dr.fuzzenstein · 17-04-2015 3:31pm

freddyuk wrote: »

You could have East/West installation? Perfectly acceptable method.
20 metres is no problem at all.

I know what you mean, 10 tubes facing east, 10 tubes facing west. I am a bit unhappy with that one, the gable is facing sout-west by a few degrees, that means the east facing side is facing east-north and that collector would get very little direct sun, or only at a very bad angle.
I could do only west facing, since that is closer to south, but I would still be unhappy about it.
On the plus side, on the gable end (almost south facing, maybe a tad south-east) it would be out of sight along with all the internet antennas and leave the rest of the house visually uncluttered.
But I don't have an attic, so where will I put the damn pipe?!

Might have to consider West (well, South West) facing...
This may just work, since I need the solar more in the summer, because then the pellet burner is off and the solid fuel stove doesn't heat the water.

dr.fuzzenstein · 17-04-2015 4:00pm

freddyuk wrote: »

There has been no degradation in performance because adding 10m of pipe is not going to reduce the heat of the fluid! If the system let's go the water turns to steam and travels all the way to your pump and expansion vessel. You are risking another disaster without a proper bypass. However the plumber will have to pay I guess.:rolleyes:

Would this indicate the need for a heat dump into the central heating radiator system?

freddyuk · 17-04-2015 4:28pm

dr.fuzzenstein wrote: »

I know what you mean, 10 tubes facing east, 10 tubes facing west. I am a bit unhappy with that one, the gable is facing sout-west by a few degrees, that means the east facing side is facing east-north and that collector would get very little direct sun, or only at a very bad angle.
I could do only west facing, since that is closer to south, but I would still be unhappy about it.
On the plus side, on the gable end (almost south facing, maybe a tad south-east) it would be out of sight along with all the internet antennas and leave the rest of the house visually uncluttered.
But I don't have an attic, so where will I put the damn pipe?!
Might have to consider West (well, South West) facing...
This may just work, since I need the solar more in the summer, because then the pellet burner is off and the solid fuel stove doesn't heat the water.

Under the eaves back to where the cylinder is? Go in through the wall and box in if required to hide it?? Not sure of your set up so can't suggest more.

Are you all pleased with your solar panels for hot water heating

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