[cloddopper]

With the 4KW.hr.solar PV system now installed up & running well we are now turning our minds to solar water heating ..

We don't know a sausage about it other than our neighbours may choose to make themselves upset again despite us being allowed to have it in place without their knowledge or consent .

How may other TAS'ers have it and how is it panning out ?
We are a two adult and one ( power shower, loving ) pre -teenager who spends far too much time in the shower running the hot water down the drain  sort of family.
 
 If you have a system would you be wiling to tell us how many in the family  and what is the spec of your system .
 
I'm going to do a bit of my own research on & off line as well,  but I do also value peoples verdicts when they don't have a financial incentive to help me make up my mind about it .

Any of your comments are most welcome.

Thanks

Dave & Alison .

[mab]

I did consider installing solar water heating but having totted up the price of the parts (solar HW tank and collector - £1000) I decided to spend 1/4 of that on solarPV (for my off-grid system), and dumped the surplus power generated into the immersion. On sunny summer days I get all my hot water from the PV.

With your grid connected system you would either have to turn on the immersion when it's sunny or install something like an Immersun: http://www.immersun.co.uk/ which will automatically divert any surplus PV power to your standard HW tank vis the immersion.

Whilst it may be fun to wind up your neighbour, by the time you have factored in the cost of solar water heater + a recommended HW tank, plus the cost and aggro' of getting it all fitted, the PV/immersun route has a lot to recommend it.

[cloddopper]

Thanks Mab ,

 I was thinking more of a simple stand alone water warming system for the boiler only perhaps with a low voltage digitally controlled recirculating pump

 We don't have a hot water tank as such as we have a balanced flue condensing combi oil fired boiler.


 I have no desire to, " Wind up the neighbours" if they choose to make themselves offended whilst I comply with the law that's their problem .   I'm after saving money long term as I move to normal retirement age , when the long slow financial starvation or decline of no possibility of earning and a massive reduction in the value of what you get starts to bite.
At present and for the foreseeable future bunging money in a bank or building society scheme is just about as sensible as burning it to keep warm .

I've long looked at current pensions / annuities and realised that the are a waste of money unles you have mega bucks indeed ,, which if you had you wouldn't bother with them in any case.
 Both of the  FIL's ( dec'ed ) lost over 2/3 of their planned incomes because of investing every penny they'd earnt in the last 40 years or so of their working life in endowments , annuities & other government approved financial investment schemes. 
 We want something in place that the government and banks can't easily steal from us .
The green energy route seems about the most helpful in our day to day lives.

As well as the green energy idea we've planned the construction and had built our 36 inch high raised garden beds of about 220 sq feet & a glasshouse etc.  so that even well into infirmity we  should be able to support ourselves in all vegetables , save for potatoes .

[regen]

If you are using oil for heating and hot water probably better putting money into insulation.  As MAB says solar thermal comes a poor second to PV plus immersun.  A 4kw PV can easily put 2000kwh pa into a water tank via an immersun.

Regen

[cloddopper]

We are four points into C banding for the official assessment .... insulation from here on is going to be very expensive.
 
Ripping out the solid floors excavating and putting a thermal in fill with  underfloor ground sourced heat  would cost around £ 30 k apparently .


We have carpets with decent underlays every where save for the bathroom which has thermostatically controlled to 13 oC underfloor heat trace cable heating to keep the wet room dry .
The kitchen has sealed carbonized bamboo flooring which is also a reasonable heat saver due to the myriads of insulating air tubes in each cubic centimetre.
 Apparently all  this has to be ignored in the assessment.

 One of the things mentioned for a big increase in energy efficiency was making the home into a sealed system with a heat exchanger & dehumidifier.
 
I looked at things and got guessimate from three different companies for over £15K
adding triple glazing and a new door was also supposed to give a reasonable increase in efficiency so long as you only put it in when the current DG is in need of replacing . 

We spent £680 on replacing shot DG panes in the first year or so  we were here .
It's a pity they didn't show up before we purchased the place or before we knew about triple glazing & sealing the place as we might have had it done and stayed at my brothers  place whilst they were away in the USA for five months.

[regen]

 "One of the things mentioned for a big increase in energy efficiency was making the home into a sealed system with a heat exchanger & dehumidifier"

This would really involve a huge investment in insulation and is extremely difficult to retrofit.

Looks as though you have done pretty much everything which could result in a cost saving and the only thing which could be regarded as a income type investment would be additional PV but it would require a G59 application to the DNO, a possible reduction in existing FIT and income tax implications not to mention planning . 

Regen

[cloddopper]

That's what we have discovered hence the solar water heating angle to reduce the oil burnt.
Putting in the new boiler , efficient  rads & 15 mm piped central heating ( insteadof our old 8 mm micro bore  ) has really dropped our oil useage down to just under  1200 litres per year against using over 3600 per year previously .

Evidently there is also a financial incentive for this solar water preheating but we don't quite know all the in's & out's of it .

 Like ...do you need to be on a water meter to take up the offer ??
 We are not on one at present , having one would cost us far more than present if the bills the old gal next door down to us who demanded to go on a meter  is any thing to go by .
 Will the incentive payments be for 20 years or less .
 
We know that the effective life of the solar water heating systems currently being installed is likely to be in excess of 40 years. So it appears a reasonable method  of getting a good ROI instead of giving it all to the banks and tax man with the present  0.5 %  ROI .

 By big brother  Bill who lives slightly further north of here in Hereford has had a solar heater for about the last 15 years , him and his wife Pat are full of praise for it .
 Pat used to be a hospital manger for all the  services in the Hereford hospital group & has always been extremely financially astute and meticulous .. she's kept detailed financial records of all her domestic monies for the 50 years plus they've been married .
 I rang her up on Friday night  and asked for her views , the pros & cons as she saw them .
 Her verdict .. we should have had both installed both in one go when it was a 40 p feed in rather than just the solar water heater .

As she and Bill are well into their seventies they don't feel that their remaining life span will see them recoup the cost a PV system  , if they were in their early 60's like me they'd go for all of it asap.

[regen]

That's what we have discovered hence the solar water heating angle to reduce the oil burnt.
Putting in the new boiler , efficient  rads & 15 mm piped central heating ( insteadof our old 8 mm micro bore  ) has really dropped our oil useage down to just under  1200 litres per year against using over 3600 per year previously . THAT IS A HUGE REDUCTION IN USAGE ARE YOU SURE THERE ARE NO OTHER FACTORS INVOLVED

Evidently there is also a financial incentive for this solar water preheating but we don't quite know all the in's & out's of it . INSTALLATION COST AROUND £4500 MUST BE MCS AND VIA EPC. PAYMENT AROUND £300PA FOR 7 (SEVEN) YEARS ONLY PLUS ANY SAVING ON OIL NOT USED (1LITRE PRODUCES ABOUT 10KWH) MOST CONSIDER IT TO BE VERY MARGINAL.  BUT YOU WOULD HAVE TO FIT A TANK SAY 250 LITRES AND IF IT HAD A BUILT IN 3KW IMMERSION YOU MAY BE ABLE TO GET 200KWH VIA AN IMMERSSUN FROM YOUR PV AS WELL.

 Like ...do you need to be on a water meter to take up the offer ?? WHY? IT IS A DEEMED NOT MEASURED FIGURE BASED ON NO OF PEOPLE AND WHAT IT SAYS ON YOUR EPC ETC
 We are not on one at present , having one would cost us far more than present if the bills the old gal next door down to us who demanded to go on a meter  is any thing to go by .
 Will the incentive payments be for 20 years or less . NO THEY ARE FOR 7 YEARS ONLY THEY ARE ONLY DESIGNED TO PROVIDE A CONTRIBUTION NOTHING LIKE THE FIT
 
We know that the effective life of the solar water heating systems currently being installed is likely to be in excess of 40 years. DOUBTFUL WITH OUT SOME MAINTAINENCE- PUMPS,VALVES,TANK ETC WHEN THEY GO WRONG AND THEY DO IT REQUIRES A QUALIFIED (READ EXPENSIVE) PERSON TO FIX IT So it appears a reasonable method  of getting a good ROI instead of giving it all to the banks and tax man with the present  0.5 %  ROI .  MOST CALCS RECKON A PAYBACK OF 12 TO 20 YEARS DEPENDING ON CURRENT FUEL ETC. BUT YOU NEED TO LOOK VERY CAREFULLY AT YOUR OWN SITUATION AND MAKE YOUR OWN JUDGEMENTS ON HOW FAR OIL PRICES WILL GO

 By big brother  Bill who lives slightly further north of here in Hereford has had a solar heater for about the last 15 years , him and his wife Pat are full of praise for it .
 Pat used to be a hospital manger for all the  services in the Hereford hospital group & has always been extremely financially astute and meticulous .. she's kept detailed financial records of all her domestic monies for the 50 years plus they've been married .
 I rang her up on Friday night  and asked for her views , the pros & cons as she saw them .
 Her verdict .. we should have had both installed both in one go when it was a 40 p feed in rather than just the solar water heater . TOTALLY DIFFERENT TECHNOLOGIES WHICH ARE NOT COMPLEMENTARY UNLESS THEY FEED INTO A THERMAL STORE WHICH ALSO PROVIDES THE CENTRAL HEATING.  YOU CAN ONLY USE SO MUCH HOT WATER AND IN THE MIDDLE OF MAY A 4KW PV SYSTEM CONNECTED THRO AN IMMERSUN WILL HEAT A 300LITRE TANK TO ABOUT 70 DEGREES C WITHOUT ANY HELP FROM SOLAR WATER HEATING. CONVERSLY IN MID DECEMBER BOTH TOGETHER WONT EVEN GIVE HALF A TANK OF WARM WATER.

As she and Bill are well into their seventies they don't feel that their remaining life span will see them recoup the cost a PV system  , if they were in their early 60's like me they'd go for all of it asap.

SORRY FOR CAPITALS ONLY INTENDED TO TRY TO ANSWER MANY QUESTIONS LOGICALLY.

Regen

[cloddopper]

Thanks Regen,

 The oil saving was not just down to the new central heating system I also did full cavity and roof void insulation , fitted a  new UPVC double glazed special draught reduction letter box  front door,  that actually fitted and closed ( it helps evidently  )
 I put four stage adjustable trickle vents on all windows so we can have say a 5 sq  cm ventilation  in a room if needed right up to almost 100 sq cm in each room depending on how In set the adjustable louvers .

 I also got a pal to sweep the chimney ( salt glazed 10 inch internal pipes for the liner ) spotlessly clean and then mortar a vented cap ( cut 2 inch thick paving slab "  on the stack so that the vent is four 8 mm copper pipes bent down to give a tiny trickle of air up the chimney to stop it sweating .
 Before sorting the open chimney it was as good as having all doors and windows open as there was no throat in the chimney  to restrict or reflect things ... we never lit a fire in it as it would have been like a blacksmith's forge on full bellows .
 
Because the new boiler is a roof mounted balanced flue , condenser type  I was able to take out & brick up the back door which had a 12 x 12 inch louvered air vent open 24 /7 vent in it to give air to the old room aspired  boiler & the fire place  .

 One cold spell when it was minus 13 oC outside , even though the old boiler was on 24/7 & I'd stuffed the unused chimney with carrier bags full of crumpled newspapers the kitchen temp was just above freezing , due to the artic blast being drawn in by the boiler .. who ever designed and commissioned that set up should have been forced to pay for the oil wasted ..

 I asked about the water meter  because I was not sure if the payments for using solar heat were in part related to a percentage of water used in the home like sewage is calculated if your connected to  a mains sewer and on a meter .

[sandalfarm]

What is the problem with the narrow bore tubing in central heating ? Is it that it becomes even narrower with a build up of deposits over time and does it still happen if the system has an inhibitor in it.by the above questions you can guess what our system is! Thanks for your thoughts

[cloddopper]

I gather that to get the heat around the system effectively the bigger bore was needed and like you say the sediment builds up . This new system has a particulate filter trap /pot that gets cleaned out on each annual service .
 I cleaned out all the old rads when  we first came here 9 years ago .. the thick black sludge in each rad was well above the mixing tube of the  inlet /outlet water at the bottom of each rad .

 I doubt that they had been citric acid & ultrasound flushed in the 30 years they had been installed .

[chrismahon]

Just to answer Sandalfarm's question. 10mm micro bore is difficult to work with and the fittings are expensive. 8mm is even worse on both accounts. But a properly designed system combining standard pipe sizes of 22mm and 15mm with balance feeds off in micro bore is the most efficient combination you can get. The radiators must be oversized to get as much heat out as possible if you are using a condensing boiler, because it is then possible to get the return temperature of the water below the conducing temperature and gain the savings. It cannot be achieved with large bore pipe work. You also reduce the amount of water heated in the system and that makes a big difference in running costs and warmup time.


Micro-bore doesn't silt up if you use corrosion inhibitor. It doesn't silt up if you haven't either, because the velocity in the pipes is too high. But what happens is the silt builds up in the centre section of the radiator gradually, blocking the flow there, so you get cold areas. Ultimately the silt drops into the return pipe and blocks it. Don't use power flushing on micro bore systems under any circumstances. Take the rads off and flush them through individually. Blocked pipes need replacing as it is a devil of a job to clear them out.


My system is 8mm micro bore. It works perfectly now after a long process of modification and maintenance.