Saturday, March 31, 2012

First morning with System 23

31 March 2012: The Kingspan Varisol tubes system is running quite well today with the System 23 setting, despite there being no Sun! The air temperature is only about 10º but is about 16º in the manifold. With the heat pump working, and putting out 5º to the ground loop, and a delta-T trigger of 4degrees, it is working busily away. It is annoying that the clock on the controller unit is in integer hours, so one doesn't see accurate times. It also seems to reset to zero every 24 hours, so if you don't note it, that information is lost. I had to rewire the controller (see below) before it actually sent any power to the pump.
   Now that this is working, I notice from the manual that there is more that can be done. An SD card can be inserted in the side of the controller unit to record activity. Also, with additional sensors, one can get the unit to work as a data logger, displaying past activity.
The controller needed rewiring because in the System 23 (swimming pool mode)
AC pump power is sent to the 'secondary' pump which requires wiring the pump wires
 to the contacts on the right hand group.

Tubes and solar controller

30 Mar 2012: Another option to get these tubes working is to play with the settings of the Kingspan controller. Jason's electrician has set up the circuit as 'System 1', but I discovered (with some manual reading) that there are other options and I may try them first.
    Looking at the plumbing in the loft, it is so neat and tidy that I am unwilling to modify it hugely if that is unnecessary. See:
The Swimming pool option is on the bottom left
Reading the manual, I discovered that there are 39 system options, one of which is an option for heating a swimming pool. System options 23 and 24 are for swimming pools, one with a heat exchanger, and one with the cold pool water circulating directly. This is hugely similar to the situation I have, with a cold energy store that is so large it will never get significantly hot - but the liquid from that is still circulating through the tubes, so there will always be a useful delta-T to turn the tubes on and off. I had a delta-T of 8 degrees on the Sunbox because you need that much to push useful energy through a wall of polypropylene. In the case of the tubes, the sensor is measuring that actual liquid in the tube - so a delta-T of 2 degrees is an energy gain.

  Well... it is night now, but I hope to find in the morning that the system is running better than it was today. Only 1 hour of running and no kilowatt hours so far. Unfortunately, the weather forecast indicates that the warm sunny week we have just had may be history. Monday and Tuesday are likely to be rain with temperatures more normal in January, maximums of 5º or 6º.... groan. If the Surya Sunbox had worked correctly, I might have buried about 100 kWh in the last six days.

Tubes working, heat exchanger needed

30 March 2012: The Tubes have been installed and are working, but we have rapidly discovered some interesting issues. Their performance is very intermittent and it is apparent that we need the equivalent of a tank or a heat exchanger. The existing Surya sunbox has not needed a heat exchanger because the thermostat is comparing two temperatures - the solar/air temperature (immediately near the black panels inside the sunbox) compared with the down flow temperature of the ground loop. Even when the system is running fast, the solar/air temperature does not cool down fast when the liquid is flowing, and it might flow for 10 or even 20 hours a day in the summer.
  The flow rate for the tubes is slower that with the sunbox, and the thermal sensor for the tubes is measuring the flow through them. What happens is that the temperature in the tubes manifold rises to 22ºC, is then triggered by a delta-T of 8, and liquid from the ground loop comes up, immediately cools that sensor to the temperature of the ground loop, so then the delta-T is nothing and it turn off again.

Jason Philips who is the solar plumbing contractor is full of ideas and it seems I have two options, because I am determined to make this work. One is to use a water tank, but I am quite against it because I don't want mains water up in the loft, and I don't want a very expensive copper insulated cylinder.
  Another is that a heat exchanger can be used - this is warmed by a flow going through the tubes, and another flow through it is going to the ground loop. The time delay for energy to transfer from one to the other is enough to keep the tubes loop going. The energy is transferred through metal plates touching the pipes.
  I could make an exchanger up, because I am handy with aluminium and copper, but this would be wrong because one major purpose of this second Surya system (using the tubes) is to use industry standard components, not handcrafted products that take weeks to make.
  My early ideas in 2009 with a tank full of PCM balls were an attempt to make a heat exchanger, but it turned out that it was not necessary (but I should have been smart enough to include an expansion vessel.). I still have the balls, and could make up an exchanger, but instead of using water as the matrix, I would probably use dry sand - but this would be very heavy!

Wednesday, March 28, 2012

Installation of Tubes

28 March 2012: The plumbers have been here from MG Renewables and JL Philips.
 Racking on the roof - one PV panel displaced, but still producing power.
 Steve is quick off the mark getting the Kingspan pumping station fitted.
 Pumping station with its expansion vessel. Looking at that made me realise more clearly what my problem with the existing system has been - these are really inexpensive and if I had known more about  plumbing, I would have fitted one in 2010.
 The plumbing at the north end of the house evolves, and the new circuit is connected (but not yet filled) and there is a volume and energy meter on it.
The top up bottle for the entire system is now lifted about 400mm to give more gravity pressure on the whole of the system. 

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 59ºC 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.

Monday, March 26, 2012

Dragons Den test: Ploughcroft

Chris and Deborah
26 March 2012: [See PS down below]: I have often wondered if there was a 'business idea' in this Solar Earth Charging lark. One way of testing this idea is to imagine myself in front of the dragons of BBC's Dragons Den, and how I would explain it to them, and how I would present the financial figures.
    I know the argument would not pass their gaze at this time - my market share could only be for ground source heat pump users with boreholes, and with the willingness to improve the performance. This is too small a prospect for any of the dragons to be interested in. Look several decades ahead, and there will be a lot in it, in fact, the combination of Solar Charging with Ground Source is what may help to enlarge this sector. This is the argument that will be of interest to Kingspan if the experiment with tubes works.

One renewable activist, Chris Hopkins, had the courage to go onto Dragons Den and face the grilling, and he actually picked up two business partners, Deborah Meaden and Theo Paphitis. His newly formed company, Ploughcroft, has what seems like the widest possible portfolio of renewables, including Photovoltaic, Solar Thermal, Heat pumps, Wind Turbines, Home Insulation and Maintenance of renewables. I am quite pleased that the first image on the heat pumps is of a ground source, not an air source. I notice that he doesn't offer Biomass, but there are probably good reasons for this.
  The company with the backing of two such well known TV personalities is bound to do better than others in these difficult times of regression of the FIT.
PS, October 2012: Ploughcroft has gone into administration, laid off its staff, and formed a new, smaller company. This is mostly caused by the same problem that all solar companies have, which is the rapid demolition of the FIT system by the Tory government, leaving many businesses with insufficient customers to make it possible to maintain the full range of staff and facilities. Sad.

Trickle all the Time

26 March 2012: I have to get used to the new plumbing circuit again. One reason I liked the old 'Trickle and Whoosh' one was that it was more dramatic in its effect. It would 'whoosh' through the upper system when the GSHP was on full load, and one would see the temperature figures change quickly as a result.
   One disadvantage of that is that it would become intermittent - it would whoosh warmer liquid down at 18 litres/min , then because the delta-T between the Sunbox and the down flow was no longer good, it would turn off.... then a few minutes later, it would come on again, have another whoosh, and so on. I am sure that this is not the reason for the solenoid valve failing because I presume it was designed for frequent use, but it seemed inefficient.
    The 'Trickle all the Time' circuit is less dramatic, because it is injecting warmer liquid at only 5 litres/minute, but this means that it does not warm up the down flow enough to stop it. I hope that over the long term, this will result in more kWh dumped - because the delta-T will be favourable for a longer time. With the higher temperature delivery from the evacuated tubes, this type of connection will be the only practical one. The existing sun box pump is now working at 45 watts, and I have yet to find out what this will work out at litres/minute. I will know after a week of averaging the flow volume and clocked hours.
My next task is to clean up this arrangement to make the
simplest possible connection for the tubes circuit
Thoughts on future performance
The summer time performance will probably be the same with either system, the diurnal may be better, but I am curious about the winter performance. In Winter, with the entire ground loop going through the panels, one can see the direct effect of a sunny winter day. I was watching the GSHP working this morning with the new circuit, and recognise that the downflow temperature isn't vastly increased anymore because it is receiving only a trickle of warmer liquid that doesn't change the visible down flow temperature much. That's less 'dramatic', but it is consistent, and there is good reason (better delta-T) to think that winter performance might improve. With the liquid moving more slowly through the panels, I hope it will have time to get more warmed. Providing the piping is well insulated, the system may be more efficient.
  I am glad I have done this 22-month trial of the Trickle and Whoosh method. If I had not, I would have wasted acres of blog-space speculating on how much better it might be - I now know that it is not as good, and it not as reliable when a maintenance issue arises.

March 2012 Reports

For those just arrived, I do a computation of the ANNUAL performance every Sunday, by subtracting this evening's meter reading from the same one, exactly a year ago. I add the weekly report to this blog diary entry, every week.

The Isover student competition stand at Ecobuild, with
the work of the best 8 students teams on show, five of which
are Nottingham groups.
25 March 2012: The week has been full of world news. There was an outbreak of shootings in Toulouse, France by a man on a motor scooter. By a remarkable piece of police detective work (tracing the IP numbers of people who had replied to an advert for a scooter), he was identified and surrounded, and after a few days he was terminated in a shootout. At the weekend, the Bolton footballer Fabrice Muamba had a heart attack during an FA Cup match with Spurs, and although he was unconscious for along time, a cardiac specialist in the crowd was able to push forward and provide help, and Fabrice is now having a slow recovery in hospital. Early in the week, the NHS restructuring bill was passed by the Tories, despite that the vaunted idea of transferring power to the GPs is almost universally unwanted by the GPs - and the public find it too complicated to understand, but just wish they would let the NHS get on with their great job without interference.
One place I had to visit was the Kingspan
Renewables stand, and see their
Varisol tubes.
Osborne produced his budget, with the tax reduction for the rich, increased taxes for the over 65s and for people wanting hot pies from Greggs, and claimed that getting tougher on stamp duty would somehow balance all this - what a massive guess on his part, and it's wrong mathematically, and it is unethical. Tuesday evening, Nottingham Forest performed a miracle and beat Leeds 7-3 at Elland Rd. How lucky for the fans who had gone up for the evening game! The Archibishop of Canterbury announced his forthcoming retirement. Ecobuild has been on all week, and my department laid on buses every day of the exhibition, and I had my chance to visit on Wednesday - and attended 90mins worth of seminars about ground source heat pumps.
    Later we heard that a human who had had his brain taken over by aliens sometime in the 80s succeeding in accepting the living heart of a cockroach, because it was the only species that his antibodies would not reject - yes folks, Dick Cheney had a heart transplant.
  Oh dear, there was another bus crash, this time in England, with a bus driver bring his bus to a halt in fog on the M1, and a poor lorry driver behind ploughing into the back of it.
  The Queen made a speech in Westminster Hall that was for once written by herself, thanking Parliament for creating a new stained glass window to celebrate her Jubilee. Later, she went to Manchester Town Hall as the start of her Jubilee tour, and became a surprise wedding guest for a couple who had chosen the same day!
How's about the Peveril Solar house?

  • 4,650 kWh for the House and 2,635 kWh GSHP, both similar to a week ago.
  • PV is down a bit at 3,422 kWh. But it is far better than 3,300, so no complaint.
  • Sunbox was  3,030 kWh, and a record sunbox clock of 2,578 hours. The disparity is a result of a sunny week stimulating the clock but a pump failure reducing the volume of liquid pumped through the Sunbox.
  • Ground temperature is 11.6ºC. It has been a sunny week, and the system has malfunctioned, but I'm happy that enough heat has been put down to lift the temperature.

18 March 2012: Every week, I wonder what will be the stories that sum up the week, and fear that there will be none -  but history doesn't disappoint. Events occur... Indeed, events that happened earlier in the week are so often eclipsed by events later, that one wonders at this pattern. Weekends can be newsworthy because of sports events, such as grand slams, Formula one, Cup finals etc.- and we have the Olympics on the way!
   Syria continues to be a very distressing story, and the pressure racks up on Iran with the war-hungry Netanyahu visiting Washington and threatening unilateral action. In Britain, ex-tabloid editor Rebecca Brooks and her husband were both detained for questioning by the Police, denying them the chance to to to the Cheltenham Gold Cup (doesn't one feel sorry for them, heheh! ). The new Kings Cross station opened, and this is a spectacular public space that has taken a very long time to build. Overweight policeman may no longer be the 'laughing policeman' if the government decides that they must slim or do more physical training to keep their jobs.
   A terrible bus crash of Belgian children occurred in Switzerland. This is the second this year that I have reported one of these winter sport crashes - how crushingly sad for the parents and school fellows, and their communities. But brighter news is that a bus on the M1 was saved when the driver collapsed and a passenger fought with the wheel and the brakes to bring the bus safely to a halt.
  Cameron has been on a visit to United States, like an eager puppy excited to be with the president, and lapping up his hot-dogs, basketball, rides in Air Force one, and other photo-opportunities. Unfortunately, he is so eager to please the US that he is likely to drag the UK into a global conflict if Israel attacks Iran. The wonderfully hairy Archbishop of Canterbury decided to retire to academia at the turn of the year, he has plainly become very jaded by the endless rows at the Synods about gay clergy and women bishops. George Clooney and his dad got arrested while demonstrating outside the Sudanese embassy in Washington. Goldman Sachs may, with luck, suffer a 'Ratner' moment as it is revealed that they work for themselves and not for the 'muppets' whose money they are using - it's uncomfortably close to a Ponzi scheme.
  Sportwise, Wales won the Rugby Grand Slam, Man United have done badly in the Champions cup but well in the League, Chelsea have been doing very well in all competitions under their new manager (even Fernando Torres is scoring!), and Liverpool are finally improving. What about the Peveril Solar House? It has been a poor week with almost no sunshine between cloudy times, but it hasn't been particularly cold.

  • 4,635 kWh for the House and 2,624 kWh GSHP, both the same as a week ago.
  • PV is down a bit at 3,439 kWh. But it is better than 3,300, so I can't complain.
  • Sunbox was  3,062 kWh, and sunbox clock of 2,565 hours. Very high figures. I have raised the Delta-T and the Real-T required to trigger the system, to reduce the hours.
  • Ground temperature is 11.1ºC. If this is above 11º with a week of almost no sunshine, then it is very encouraging.

Putin.... emotional at his victory
11 March 2012: Another week of news, and it ended on a very sunny weather note. During each week, I think its a slow news week, but gradually it builds up, and there is plenty to report. Also, I find it interesting to go through old reports from previous months, and am amazed at how quickly events get forgotten, or become less or more meaningful - depending on how they affect later events.
   The week started with a fireball crossing the UK from north to south, but experts said that it was very small - the size of a fist? It ended with a major solar flare and some Northern Lights visible over parts of the UK but I haven't seen them - there is no city to our south and we have a splendid view of the stars, but to the north is the urban light pollution of Nottingham. Further away in Russia, Vladimir Putin managed to win the presidential election (against who?) and claimed it was 'Glory for Russia' thus assuming he is some sort of god personifying the country.
bye bye David
In the other direction, it was 'Super Tuesday' for all the crap-faces of the Re-thug-lican party, and who gives a damn who won any states? They all did except for Ron Paul, and they are all crazy shits. Earlier in the week, Brazil's economy overtook the UK's although they still have 3 times the population.... so, some way to go there to catch up on the per capita basis. Six British soldiers were killed in Afghanistan which prompted the usual politician's protestations about the important of completing the mission - the same old arguments which have been used in all de-colonialisation processes - "we can't leave or there will be a sectarian bloodbath", and "we can't leave or it will dishonour those who have already died in the war so far". And at the end of the week, an American soldier threw a wobbly, and went out of his base and murdered 10 Afghans in their houses - the sort of random killing that happens routinely in schools in the US every few weeks, and goes almost unreported, but will have very lasting consequences for the US's Afghan occupation.

Poor not-so-old Davy Jones of the Monkees died peacefully in Florida, bringing back memories of the sixties... Monkees are (for me) the only group other than Beatles, Stones and Floyd where one knows most of their names. It was the anniversary of the Japanese Tsunami, and the BBC carried a good website of images, Then and Now, revealing how amazingly well organised and hard working the Japanese are to tidy up their cities. And talking about good things coming from bad, there was the event in Brazil of dolphins being beached, and being saved by the good nature of the people on the beach who pulled the dolphins back to safety. Oh, by the way, it was my birthday on the 9th March, and my two large children turned up for the weekend.

  • 4,630 kWh for the House and 2,625 kWh GSHP, both reducing nicely, recovering from the cold spell of early February.
  • All time record for PV at 3,449 kWh. This has to return sometime, when the rain returns. But it has been a good March for sunshine so far.
  • Sunbox was  3,088 kWh, and sunbox clock of 2,564 hours. Very high figures. I have raised the Delta-T and the Real-T required to trigger the system, to reduce the hours.
  • Ground temperature is 11.6ºC, unusually high for this time of year, but entirely expected after the wonderfully sunny Sunday.

4 March 2012: For the world it has been a busy week, and for the house here, it's been a week of reverses. For the world.... Syria just continues to be a brutal story, and US/Israeli paranoia about Iran keeps threatening to turn into military action. What a mess. If you initiate war action when it is not self defence, are you not guilty in international law? I have had a number of Iranian students in recent years, and it distresses me that ordinary Iranian families will suffer. We know from 1914, 1956, Lebanon, Gaza, Bosnia, Kosovo etc. that these things all have 'mission creep', i.e. they escalate into more serious actions that exceed the aims.
    Elsewhere... the cruise ship Costa Allegra was stranded in the Indian Ocean after an engine fire, and was towed to safety by a French fishing trawler. England declared itself to be in a state of drought after three dry winters running, while Scotland has had a surplus of rain - suggests the idea of a water super grid. The Oscars happened at the start of the week, and gave it for the best film of the year to The Artist, a silent movie. Occupy St Pauls were forced to leave, in the same week that Barclays were found to be tax avoiding by hundreds of millions of pounds. The country was obsessed with the fact that Cameron may or may not have ridden a horse of Rebecca Brooks, and after obfuscation, he admitted that he had... and James Murdoch stepped down as head of News Corp.
    Finally.... Englebert Humperdinck is likely to be the UK's singer for Eurovision Song Contest 2012 - a mere 45 years after relaunching his career, and 89 years after the real Englebert Humperdinck died. 
The two Engleberts....
  In the Peveril Solar house, I had the Surya system fail on Thursday, and this turned out (investigating during Saturday) to be the actuator on the Danfoss 2-way solenoid valve. We lost the energy capture from a very sunny day on Thursday, and with Sunday being cold and grey, the ground temperature is back to 10.8ºC.
  • 4,636 kWh for the House and 2,641 kWh GSHP, both improving nicely, recovering from the cold spell of early February.
  • All time record for PV at 3,448 kWh. This has to return sometime, when the rain returns. Either that or I should check the figures for the previous year!
  • Sunbox was  3,090 kWh, and sunbox clock of 2,538 hours. Very high figures. But I must sort out this solenoid valve problem quickly!
  • Ground temperature is 10.8ºC. I was hoping for 11.0 but after such a cold rainy Sunday, and missing three days of Surya benefit, I guessed it would be about 10.8º.

Electrical problems

Electrical problems
I need a new pump.... probably
one of these Wilo's
Along with this I had a dual electrical problem. I thought it was the Pump, and then discovered that it was the Valve, which was not delivering power to the pump. I replaced the valve actuator and that worked again, but the problem persisted intermittently. It worked, but the system has had very poor performance during the last sunny week with very poor volume transmitted, and very few kilowatt hours - but many hours on the clock!
    I discovered (while checking for airlocks) that the three-speed Pump is not working correctly at the low speed, which is 30 watts. In fact, the 30 watt speed worked briefly while I was looking at it, and then failed completely while I was looking at it. This explains why the sun box system only seems to have worked when the GSHP activity was driving it, but the clock was driven by the Sun, so it recorded high figures. The other two pump speeds, 45 watts and 65 watts work fine, so it is now set to 45 watts. This runs mostly in the daytime when the PV is working, although I would still like a lower power unit.
   The pump should be replaced because it is old and no longer working at the preferred speed. Most normal DC pumps are about 60-70 pounds, but they are all rated for heating with a lowest liquid temperature of +2ºC. As our system is using refrigerant and going below that line in Winter, I investigated colder pumps. Ones that can go down to minus 10ºC are more than 200 pounds, dammit. As this is a normal rating for circulating water, I guess that water at below +2ºC would be having local icing up spots. We are running a solution of anti-freeze, so I will risk getting the standard low cost Wilo pump, but the A or B rated energy efficient one.

Major plumbing change

This is the arrangement from May 2010 to March 2012
25 March 2012: The plumbing arrangement has been significantly modified. In May 2010, I changed the whole circuit operation from what I called 'Trickle-all-the-time' to 'Trickle-and-Whoosh'. This seems to have worked well, but I have been troubled with technical problems recently, and the change had to occur. This was for me, a big adventure and as I do usually, I kept finding something else to so, procrastinating until it just had to be done. So it was a Saturday Night and Sunday Morning job! taking it apart on Saturday, sizing the pipes and fittings. Sunday morning, I puttied up the joints and tightened them up. Nothing leaked! Hooray! Then the big pressure bottle had to be refilled. (In so doing, I discovered that the Pump has gone faulty - it spins, but does not impel.)

Simplify the circuit
The advent of the Varisol tubes has forced me to make this change - I have been thinking about it since January, and did some very complicated diagrams designed to keep the previous design layout, and add the tubes. I had a brainwave during a Forest football match while we were being beaten 2-1 by the bottom team of the League, Doncaster.
New arrangement on the garden table
   So, I came out the winner, having realised that if I change to Trickle-all-the-Time, the tubes could be connected at the existing loft location without any modification to the ground floor, without any vertical piping, and almost no modification in the loft either. Getting rid of the solenoid valve and fitting a non-return valve instead is removing a major source of future problems.

Performance benefit
I can see that there could be an improvement in performance and reliability with the new circuit. With the whole flow going through the panels, there is a risk that if the sun box has a major problem then the entire heat pump cannot work, and this could occur in winter. This has happened this month with the failure of the valve and pump. The circuit requires very large piping and fittings - if I had the simple trickle method, I could have used 22mm or even 15mm piping. When the heat pump has finished a heating cycle, there is a period during which very cold glycol continues to circulate into the borehole running the energy meter in reverse, and cooling the borehole because a large amount has to be flushed through.

New circuit arrangement, simpler and more reliable.
(prior to fitting thermal insulation).
The circuit diagram has to be updated now, for the website and for the next article.

Sunday, March 25, 2012

Savita: end of the line

25 March 2012: Readers who have followed this blog may have wondered why the current Sunbox is called Surya-3....
  what happened to model number 2?

Well here it is, in the process of deconstruction and recycling. I made it in May 2010 in a fit of enthusiasm, thinking that I would make a PV-Thermal panel using the same principles - got the sun box made, got the radiator, got the energy meter, pump and thermostat - but somehow, I didn't want to knock more holes in my wall and the original Surya-1 Sunbox was doing well and it seemed wrong to upset the data capture for that. Blaise was not keen, and it seemed that you should give each stage of the project a year to prove itself before moving to the next design.
  The energy meter, pump and thermostat were erected on the system in East Leake, but regrettably, the plumbing (that I did NOT do) was so leaky and badly done that it never worked efficiently, and I haven't yet recovered that kit - all that is needed is some fixes to the plumbing and it will work. The Plumbing method is the same as I have now changed mine to for the Peveril Solar house.
  This Surya-2 (which I called Savita) has been in the garden for nearly 2 years, but I don't intend to erect it or do any more with it. However, the lineage of the current design is evident, with the 70º slope at the front. Also, this was built in record quick time, as an experiment in 'value engineering', i.e. being able to make a sun box in such short time that it becomes economic to use on other houses.
Previous History:
Savita Radiator painting
Savita first view of model

Backboard for Pumping station

24 Mar 2012: The Kingspan pumping station for the Varisol tubes will need a location, and that will be at the north end of the loft. I have managed to find some scrap bits and build a backboard for it between the trussed rafters, with some gaps between the boards (I have a spare board if Jason wants the backboard to be solid).
 We are going to use flexible pre-insulated piping, which may cost more per metre, but is very very labour saving and doesn't have joints that could leak!

Friday, March 23, 2012

Scaffold is up!

22 Mar 2012: The scaffolding is up, for the next Solar adventure. I am told we can expect to be doing the installation on the 28th March - just in time for the start of the 'summer semester', starting April 1.

Tuesday, March 20, 2012

Tubes: Reconnaissance and Scaffolding

20 March 2012: Progress is being made on the proposal for some evacuated tubes on the roof.
    I have had a visit from Jason Phillips (of JL Phillips), representing M & G Renewables, for a reconnaissance of what needs doing for the tubes. There is not a lot, as the plumbing downstairs needs a small modification, and the rest is in the loft.

Downstairs, I shall get rid of the 3 port valve, replacing it with a non-return valve. We have an almost plug-in-ready connection point in the loft for the additional circuit - just needs to be modified slightly from my existing layout. There is a convenient location for the pumping station, pressure vessel and energy meter, I only need to fix up some more timber panel to fix them to. I will ask for the thermostat-control unit to be downstairs next to the existing one, next to the heat pump.
   Therefore, I have rung Richard Pearson (of Pearson Scaffolding) to make a start on a scaffold for the rear wall. It will go up between the two drain pipes. The PV should only be down for a day while they fix the metal rack to hold the tubes. 

Sunday, March 18, 2012

Mylar on the upper mirror

Night photo, with some iPhone lens flare. the right half
of the Mylar is stuck on, the left half is flapping.
17 Mar 2012: I have finally had the courage to go up the ladder to the highest point, and have a go at increasing the reflectivity of the upper aluminium reflectors - I want them to be more like 'mirrors', as they were first intended. Mylar is difficult to handle as it is incredibly thin, and blows around or away in the slightest breeze - although it doesn't crumble like aluminium foil. Also, it tears at the slightest provocation - it is quite strong in the surface tension, but if there is the slightest scissor-nick in the edge, it will tear rapidly from that edge defect - carrying a cut sheet is difficult if it is also blowing.
  I have done the right hand sunbox reflector, the one that has the thermal sensor in. I noticed a week ago that the temperature inside got up to nearly 60ºC, and the only change had been the Mylar put on the inside mirror position. So I look forward to the next sunny day to see if the external mirror has an effect. If we have a windy day, I am willing to be philosophical if I see the Mylar hanging by a thread in the wind. It is only held on with patches of duct tape, not a continuous strip. That may be a mistake, but it was getting dark and I don't enjoy being up the top of the ladder.
Daytime photo on a sunny day. The Mylar is more reflective,
and slight wrinkles are due to the use of spots of duct tape,
rather than on long section of tape. If these were on the ground
they would get a long line of tape.
Poised on a ladder at 6m altitude, I am less fussy.

Progress with Bottle Store

17 Mar 2012: The bottle store under the staircase now has 55 litres in it. I have now brought some order to chaos by building a metal rack to store them under and on. They are lined up along the heating pipes, which although insulated, still emit warmth. This 55 litres isn't worth a lot yet. Using a calculation of thermal capacity, currently, it's worth about 0.65 kWh of heat, assuming that the bottles warm up to about 30ºC during the heating time and release to a house set at 20ºC. Of course, during the summer, the heating is off, but the bottles will act as a cool mass in the centre of the house, by absorbing air heat - opening the door will release coolth.
   There's still room for twice that number of bottles, and I shall aim for more than a kilowatt hour's worth - over 100 litres. As the floor slab in the stair store also has underfloor heating, that is also worth a few joules, perhaps 0.9kWh if one assumes a delta-T of 10degs.
    It does seem to be working - in the evening, I can turn the heating off, open the store door and warm air floods out all evening.
    The racking is currently supported on bricks, and sometime soon, I shall reconstruct the legs with some off cuts of aluminium sections, for lightness and greater stability.

Friday, March 16, 2012

Largest Geothermal project in US

15 mar 2012: One of my very best friends from the 1970s has been a Professor at Ball State University in Muncie, Indiana for a long time, and I was very pleased to read this report about his University. BSU is installing a comprehensive ground source heat pump system - not for one building but for the entire campus. 3,600 boreholes are being drilled, with a network of pipes, of over 1,000 miles! These will provide cooling in summer - dumping heat underground - and heating in winter. This will make it possible to remove the old boilers from their present district heating system, saving an estimated 85,000 tons of CO2 emissions annually.
 see the report in and on the Ball State Uni website.

Sunday, March 11, 2012

More liquid needed in system

11 Mar 2012: I noticed that the topping up bottle in the loft was a bit low, but when I cleared a few airlocks in other parts of the system, the whole lot of visible water disappeared.
    I then used a 4 litre bottle and funnel to top the pressure bottle up, and needed about 8 litres to get it right. A bit more and then a bit more air would escape. I wonder if the airlocks have affected performance, I am sure they have. But the level is correct now and I don't detect more airlocks. I noticed while doing the Mylar inside that there was a bit of gurgling, and this can indicated some trapped air.
   I didn't add more glycol, as there is plenty in the system already, and more will be added when the evacuated tubes are added.

Mylar in the loft

11 Mar 2012: Hmmm perhaps I am getting too enthusiastic with the Mylar. Here is a photograph (evening shot) of the side reveal of the Velux roof light in the loft, with a Mylar lining, fixed with robust duct tape. The idea is to make the loft a bit brighter in the daytime.
   I have now mylarred one reveal in my home-office to see how that looks in sunlight. Looks good in daylight... but paradoxically, as you can see in the photo, a night time shot shows that the light emitted from it is nothing, its reflecting the darkness outside. A white reveal is the most all-round solution. But I am still going to try it on the reveals that face south.

Mylar inside Sunbox

11 Mar 2012: I have been up the ladder trying to find uses for my roll of Mylar. The interior mirrors on the floor have been ineffective in aluminium, so they will now have a shiny Mylar surface, for upward reflection. Their position is intended to boost summer time productivity. 
Surya Sunbox with the front panel open
Solar angles at midday solstice
This was my first serious bit of maintenance since the panels were built, and it's great that the panel fronts opened correctly and the laboriously built jackstays held the panels open at the right distance for maintenance access.  It's fun to get the boiler suit on and shin up the ladder (with a helmet and safety rope, of course)
I shall also put mylar on the upper mirrors which were intended for boosting the performance in Winter and Equinox. They were very effective in their first year, but seem very grey now. Their angle is such that they are not effective in summer because I was worried about overheating inside - but in morning and afternoon summer angles, they are helpful.

Using Mylar to make mirror

Mylar glued to aluminium using contact adhesive -
Very Very Wrinkly!! (but still reflective)
11 March 2012: I bought some Mylar by mail order, 1.5m x 5.0m on a roll. The idea is to try and see if the mirror function will work better now that the aluminium is so tarnished. Mylar reflects about 98% of radiant heat energy falling on it. It is used in horticulture for increasing light falling onto shaded plants, and I note that it is used for indoor cannabis growing, something I don't intend to do!

The Mylar is not mirror finish, but it is very bright, like very clean Bacofoil, and being plastic, it doesn't crumple like Bacofoil. It is double sided, and very slightly transparent.
Mylar, highly reflective, but inexpensive
  I wondered how to fix it, and it turns out my son is also thinking of how to get a mylar-type finish on a larger item that he is building, a full size flight simulator. He has access to industrial methods, but I only have my bench in the garden.
   My idea was to tape it on with exterior quality duct tape, but we thought I could experiment with contact adhesive, using the mirror that is over the kitchen window.
   Here is the first result, using adhesive. It looked fine when I first did it, but after 18 hours, the surface has resolved into a complex pattern of wrinkles. The mylar has glued well, but any air trapped could not escape, and small air bubbles grouped together. It is very brightly reflective, but energy is scattered, and I don't know how it will weather. A smoother finish is required.
The aluminium reflectors look bright in this
photo, but it is relative - they are very
tarnished. Mylar would change them

Fastening to upper mirrors
If I had an 'industrial' method such as a power roller, I could roll out the small wrinkles, if working on a flat bench with sprayed contact adhesive. The mirrors on the Sunbox are not detachable easily (without a scaffold) and for quick attachment without adhesive, at high altitude, the tape seems to be the only method. I don't go up the ladder very often, but get slight herby-jeebies every time, wondering if it is my last time!
  Taping would be more easy to stretch to get a more optical finish and smoothness, and it would be replaceable every few years, as tape can be replaced and Mylar is very cheap. The carriage cost as much as the roll!

The interior mirrors also need some Mylar, and as these are not exposed to wind or weather, they would probably be easy to tape, and very long lasting. At the moment, there is some aluminium sheeting in there.

Sunny day in March! Sunbox work well

Surya Sunbox control unit. The upper picture displays a
high temperature in the Sunbox, and the lower image
is the temperature of liquid going down to the ground.
32ºC? I have never previously seen one higher than the mid 20s.
11th March 2012: Today is exceptionally sunny and clear, with a very high PV score, not quite as good as 5th Match, but still very high.
   For me, with the new valve actuator fitted, I was glad to see that the sun box powered its way past the 20kWh mark and it is still mid afternoon. I expect it to continue storing heat-energy late into the evening. This is the first major test in 2012 of the new insulated design. I had some excellent days last autumn at the end of September, and we are having them now.
   I am planning to change the plumbing arrangements, but for now, here is an update. I have never previously seen the Sunbox temperature more than 45º, but today, it has been in the mid 50s for much of the day, and I witnessed it peaking at 59.7ºC (and it may have briefly touched 60º while I did not see it) It is tedious standing there hoping for a change of single decimal points. So I just have to hope to check it, and find a high figure (need a reliable datalogger)
   Perhaps this demonstrates that the work on the new design was worth doing. Our annual solar capture is now consistently around at 3,000-3,080 kWh, whereas with the earlier design, it hovered around at the 2,950-3,000 mark. Also, the air temperatures were cold this morning, but with the insulated construction, the sunbox got going even before I was out of bed, with help from the morning sun.
Solar capture for 11 March 2012

Thursday, March 8, 2012

Revised circuit diagram

8 Mar 2012: The modified circuit diagram for the dual system is enclosed. One single pipe will go up to the loft, and up there, it will divide into two directions - controlled by a couple of 2-port valves. The existing pipes will be used.
Circuit diagram for Surya Sunbox
 and Kingspan Varisols

  It is odd how the progress of human affairs often moves from complicated ideas that get refined to effective simplicity.
   The revised circuit diagram is caused mainly by the failure of the Danfoss, but this has turned out to be a piece of luck as the resulting diagram is simpler and will be cheaper to plumb in - no nightmares of pipes coming through the floor, less risk of system losses, easier for maintenance, and easier to replicate elsewhere. Two solenoid valves will still be needed, but they are cheaper and more easily replaceable in the future event of a component failure.

  I have realised that the system will work more efficiently when I return to the 'Trickle while we Work' mode of plumbing. After the heat pump has done a cycle, it continues to move liquid round the circuit to clear what is in it and send to the ground, but it is sending cold glycol! With the Trickle mode, it would recover back to a normal circulating temperature more quickly.

  (Note, this circuit diagram is symbolic and doesn't show minor details such as airlock removers or precise details of tees etc. There is still the question of whether I include a water tank in the linen cupboard above the GHSP.)

Postscript: One of my colleagues in the University, Dr Chong, has pointed out that when both the Surya and the Varisols are running there will be a short circuit between the two, and I need a non return valve in the Varisol circuit to prevent this.  This is because when they are both working, the Surya pump will work at 5 litres/min and the Varisol pump at about 1 litre/min. So instead of pumping around the ground loop, the liquid will take the line of least resistance, flowing back through the Varisol pump. So the above diagram has been amended to show one.
  As the drawing looks more like a London Underground map, I also followed his suggestion to make the junction in the loft look more like a Manifold, and to consider reorganising the plumbing likewise.

Wednesday, March 7, 2012

Pump or Valve problem again

7 Mar 2012: The Valve actuator only worked for a day and then went dodgy again. Unless one moves the lever manually, it doesn't have the strength to open the valve again. The price of a replacement is about £60 and I don't want to send good money after bad. I have a spare 3 port valve, so I have fitted the Actuator from that, and let's hope we get some good service from it. I am planning to take the entire valve off by the end of this month, so it doesn't have time to go wrong again!

5 Mar 2012: Again, I noticed that the Surya pump was not pumping, and again this was down to the Danfoss Solenoid valve actuator. However, I noticed that under the valve has some very fat pipe insulation that is pushing against the underside, and I wondered if this is the cause.
When I take the actuator off, it works, when I put it on, it was intermittent.
So I cut away some of that insulation. Perhaps that is what made me rush off in a panic in January and buy a new Energy meter that I have not yet fitted.
  It is working today!

Dump the Danfoss

(this is a two port, that I will fit on the circuit
in the loft, and I will remove the unreliable
3-port that lives above the heat pump)
6 Mar 2012: I am so annoyed that the Danfoss solenoid valve wasn't working again this morning.  Once I 'helped it' by pushing the lever in the morning, it seemed to work for the rest of the day. But it's no longer reliable, and needs a daily push start like a worn out car. A failure after less than two years is very disappointing. A system like this should be able to work consistently for some years, reliably. I have a spare actuator, although it will be temporarily fitted, as I don't want the replacement going after less than 2 years.
  During some slightly boring bits of the Nottingham Forest v Doncaster match in which we saw them losing 2-1, my mind wandered off and I realised that if I dump it and replace with a non-return valve (that I took out in May 2010), the system will work more reliably - one fewer electrical part to go wrong.
    It will be back to the "trickle while we work" plumbing mode - more appropriate to future installations in other houses.
   The really big Plus would be that the future installation of the Kingspan Evacuated tubes is suddenly made a lot cheaper and quicker. The saving in plumber's time will be huge because no pipe will be required to come down through the house to the heat pump. The tubes circuit can attach to the pipes in the loft. They will simply require a 2-port Valve for each circuit, and it will be a Honeywell or another make. I might be able to make use of the existing two dummy ports in the loft circuit.
  I will work up a revised circuit diagram of the simpler solution.
  It just goes to show..... Sometimes, you think of the best ideas when you are meant to be doing something else!

Sunday, March 4, 2012

Manifold Insulated

3 Mar 2012: The external manifold has now been insulated. I found a bit of pipe insulation for 40mm piping. Also, I deduced that the rain has been pouring into the manhole, although mostly on the east side. The insulation there is totally drenched, and so heavy that much of it has fallen off. On the west side, its reasonably good, damp but not wet. With this wet insulation and freezing winter air temperatures in there, it must have caused a significant loss of efficiency. I notice that the pipes entering and leaving the manhole are insulated, thank goodness the plumber did that.

  I insulated the pipes that I could, then considered how to deal with the rain. I can't see a drain hole for water to leave the chamber. I shall have to open it on a day of rain to see what is happening there. If it fills up entirely with water, I shall have to drill a drain hole somehow - or put some sealant around the gap where the lid fits.

  There's no wind or UV degradation down there, so I reckon it is OK to put bubble wrap in the hole, arranged over the pipes to clear rainwater, but also to give the pipes of the manifold some additional insulation. So the entire manhole looks like it is full of a weird kind of white filly underwear, or some vast incubating bed for some aliens.
  I have tried to caulk the opening around the edge with polythene, but I don't think this will be totally successful. I might consider the idea of the old canal builders, which is to caulk the edge with sticky CLAY, well worked into the groove, then replace the lid, and it is 'puddled' !

Saturday, March 3, 2012

Progress with Sunbox pump

3 Mar 2012: I am slowly stirring myself to look into this, there is the time and daylight, and it's a matter of remembering how all this works, then to tackle each part using logic, multimeter, guesswork and deduction.

  1. Fuse hasn't blown, as the Thermostat comes on when you switch on the socket.
  2. The Thermostat correctly reacts when there is a real-T or a delta-T and it sends a signal to the 2-way Valve.
  3. The 2-way Valve is opening, because when the circulating pump in the heat pump is driving the loop, the glycol goes up to the Sunbox, and through the old Energy Meter and the Volume meter on the way back. But it is running more slowly than it should be.
  4. There is NO AC power to the pump in the loft. So I don't think it is a pump failure. 
  5. When the heat pump is sleeping, the thermostat says that it is sending liquid to the loft, but there is no circulation.
I need to put the loft pump onto a 13amp plug to make sure that is working, because if I am going to bother to replace the energy meter, I should seriously consider replacing the pump with a new one, guaranteed to work to -10ºC working fluid. This one is probably only rated down to +2ºC, and it is an ancient second hand one.

More to follow. Time for a tea, and then continue with investigation.
This is the actuator that was sticking. The metal lever to the left was a way to unstick it,
but I didn't realise until I had taken if off. But the spring needed lubricating, anyway. 
 Problem Solved
  1. I discovered that the 2-way solenoid valve was opening only partially, and if it does that, it allows some liquid up to the panels only when the GSHP is running. One can tell this by the noise it makes when closing. If it closes correctly, you can hear the spring working from the other end of the house.
  2. There was no power being returned from the Solenoid valve. If it is fully opened, it sends 240vAC to the pump in the loft. 
  3. The actuator is removable, and has a lever you can push to free the actuator if it is stuck. I added some cycle lubricant to the spring, and checked that it worked, then replaced.
  4. Everything is now working as it should be.
The actuator back in place on the 2-way valve, to the left of the vertical insulated pipe.
Pity, we lost all the lovely solar heat from last Thursday! I am kind of surprised, as I would expect these valves to have a longer service life between repairs. They only have a 12 month warranty which seems a short time for something that becomes part of a heating system in which you would not expect such early failure.

External Manifold

3 Mar 2012: Lovely sunny day, and Forest are playing away, so it's a good day for some maintenance. the main task is to get the pump working, but while doing the maintenance, I thought to look at another part of the system that I have neglected until today.
   Here is the external manifold manhole which I have never looked into before.
First problem was how to open it, as it is very heavy and cannot just be levered up. Needs a proper lifter, in fact, two of them. So first task was to make a pair of manhole lifters from aluminium. These now work perfectly.
Once lifted, I can see inside. The MH is lined with concrete with a concrete bottom, good so far. I see that some of the pipes are uninsulated, or the insulation has been loosely fitted and fallen off. No wonder there was some spare insulation left over after the work was done. I've used it all now in other locations, so will have to make some more insulation to wrap the pipes with. This location must have been a bit of a 'system losses' location, as heat lost to the winter air is truly lost. So this must be done before the end of the summer. 

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