Integrated woodburner, solar tubes, oil combi and underground heatstore.

[noelsquibb]

Hey you could slide down this roof and jump onto the ground without injury.
The regs are obviously for working at height 

[desperate]

Evenin Noel

I am struggling to get my head round your hydraulic layout, any chance of a circuit diagram, pleeease.

Desperate

[KenB]

Excellent stuff Noel,

I think you might have started something here  - enjoying a beer whilst catching up on the latest installment.  (No drinking in class!)

From the opening line - it sounds like something has to be working successfully ;-)

I'm having to have a lovely hot deep bath every night cos my Wife seems to like having the fire lit and theres just sooo much hot water. Sorry not to have got back sooner.

I'd be interested in some of the temperature data from the thermal store - such as heat-up/cool-down rates.  Is it actively working now from the woodburner?



Ken

[chickensoup]

   Noel,
             Cool veranda, that looks so neat,you've done a smashing job there! complimented with a quality panel. As for the rest, your MAD!

          chicken

[noelsquibb]

Desp -

I had a very nice diagram that I drew a year ago, then I went off and built it all up.
Two rather different beasts now.
I will draw up an as built schematic, because its not fair on some poor plummer turning up in the future and me not about for whatever reason. I kind of only want to do this once though and its still a work in progress.

Chickun -

Thanks mate. You see the standards I have to achieve and all that veranda just so I could put up some toobs.
Got lucky with the decking though. A mate had to lift a load that was about a year old and it had both sides machined. We turned it and used the 20mm wide grooves rather than the corduroy side and it looks great.
There was talk of slate ......



Ken

Yup a beer by the fire, whilst catching up on the SUY posts, or even in a long hot deep bath, whilst contemplating, is the way.
And you are correct, the WBS is connected to the underground store and working.
The store is 2m deep, 0.6 wide and 1.2 long, so stored volume is around 1400 litres, with a bit of room for expansion.
I have temperature probes set at  0.2m, 0.4m,1.0m 1.5m and 2m. deep measured from the top.

Theres generally a top to bottom gradient of 10 deg c whether loading or at rest. The top part of the store tends to get cooled quicker when demanding heat, so after drawing a bath the top meter will be close up by a degree or two with the bottom maintaining the gradient.

The most amazing thing is the overnight change, when no hot water has been drawn ( i.e. no cold had been through the DHW exchanger ).
It might drop a degree or two and the gradient remains the same.
So I can go to bed with a 62c bottom temp, 72c top temp and in the morning its 60c-70c.  Better than I was expecting, given the discussions here about heatstores and insulation. I guess that a foot of dry material then in the ground for a bit more reduction in heat transmission must be ok.
The heatstore lid has 100 mm of cellotex, then a layer of Tri Iso 10, then some plastic sheeting, then closed up wooden decking.

A hot bath only seems to knock a degree or so from the store but to get the best performance I have to run the hot tap a bit slowly, otherwise the  reversed TMV diverts it through the combi boiler, which I am happy to report accepts water at temps up to about 50 c ( this can be tinkered with too ).
I will at some point reconfigure the accessible bit of the DHW heat exchanger to try and grab a bit more heat from the top of the store.

Doh,    now you've read the ending you wont want to read about the day "things got a bit exciting ....."

stay tuned

noel

[Stuart]

that's some serious plumbing in that pit

[noelsquibb]

Ok, the effect of  3 months away from the project -
I completely lost the continuity and the plan that was burning so brightly in my head, sort of flickered and died.

Eventually managed to get back on it though -

A bank of 6 x 10mm tube of various lengths was assembled for the temperature probes. Five cheap and simple hand held thermometers with probes on a 1m long wire had been sat in a box for a while. I had cut into one of em and extended the probe wire by 10m and tested it to see if it still recorded anything like the same temp.
Yup no problems there.So they all colour coded and wired in to the boiler cupboard.

But when I opened up the heatstore to do the temp probes I was a bit shocked to see that the water had turned brown, staining the top radiator and the top spec armaflex, that I had carefully wrapped round the pipes that carry cool or cold water to or from the bottom of the heatstore, had been eaten by the water. Ph 6.5
and delivered ( via a pipe )  to the property as drinking quality.
I phoned up the supplier to ask if there was a better product for insulating pipes immersed in water ( could be in an underground environment with high groundwater ) and they were at a loss. They suggested I phone the manufacturers tech help line and I don't think the guy I spoke to believed me.

The other challenge that had me puzzled was how to finish off the top inside edge of heatstore to create an inward sloping 'bench' that covered the plummin and ensured any water from condensation or expansion, drained inwards without any getting into the insulation layers. Shaping it with expanding foam did not work very well, so I decided to use another resource that was lying around. Cellotex sheets being used to insulate some old shed walls, were being cut up and a pile of 'crumbs' was just lying there waiting to be swept up and burnt.  Why not mix the crumbs with cement and use the mix to haunch the edge to cover the plumbing and create a shape that will turn any water / condensation back into the heatstore.  Yeah, lovely stuff, easy to work with too. And such good insulation qualities.
Once the 'celloment' layer had dried the GRP layer was completed  and the next challenge was how to replace the water damaged HT Armaflex with insulation that will not melt if the water is close to boiling and will not dissolve in the heatstore water. I opted for some class 'o' Armaflex. Its only guaranteed up to 80deg c but seems to be a different material from the HT mix. The cheapo closed foam grey pipe lagging would be ok with being immersed but it deffo melts at about 90 deg cos I've tested it.

The next task was to install the new WBS.  As I was not about to dummy it up for approval of the height it would sit, I had to take a firm line and wave a bit of cardboard instead, cut to the size of the fire. This got me the answer I needed. Legs approx 6" long required and apparently not an option from the supplier.
Hmmm, think theres a couple of really old bedsteads on the mine scrap heap. Heh, ideal !  nice curved and tapered steel legs about 10" long.  Whizzy wheel to the required length, weld on some new footplates and we've got four perfect legs for the fire.
Next up was to  measure the volume  of the individual boilers ( to work out how much inhibitor and antifreeze I might need ) then connect them all up as per the instructions. Because there would be no upward flow from the fire, I had to sort out a bleed valve at the top outlet. So I took one of those brass bleed assemblies that fit into half inch internal BSP and ground a bit of a level place on the 28mm knuckle bend, drilled a suitable hole and it all sat very nicely. Took it to the M&E guy on site who had oxy- acetylene and got him to try and braize it together.  Oh dear, the fittings went liquid about the same time as the brazing rod. 
Further inquiries got me scrounging a short length of silver solder from the local hydraulic hose supplier ( as I said, that's where my enquiries took me ) and this was then blobbed into the remaining bits of metal. The WBS boilers and connections all air tested to 6 bar and held up for 24 hours so the silver solder seemed to be ok.

Fire in da hole and then another of the few benefits of being called away for the summer. The supervisor for the M&E subcontractors on the skool project, just happened to have some bits of 6" dia 316 stainless steel flue pipe, including two 45 deg bends and straight bits that would fit snugly inside / outside each other,  allowing me to create a perfect set of pipes to connect the fire to the isokern flue, whose bottom section is cast into a reinforced concrete register plate. I even purchased some stainless steel screws to locate the bits and some proper flue jointing stuff. A trip to the nearby Lidles was required, to get the universal currency for payment -  a few bottles of traditional ale (-;

As  I could not light the new log burner until there was somewhere for the hot water to go, I was obliged to do the final connections into the boiler cupboard for the domestic hot water.
So the cold feed to the boiler was diverted through the heat exchanger that picks up heat from the heatstore then through a reversed TMV that acts as a thermostatic valve to divert hot water past the boiler, or cool - cold water to the boiler to bring it up to temp. A further TMV was fitted to blend the incoming water back to a safe temperature if it's too hot.

Eventually,  I had the chance, with no one home, to do the job. Displacement activities finally ceased around midday, the system was shut down and the all important first cut was made. No going back now.

By about 3.30 it was ready for switch on and testing.  As the system filled and the pressure built I saw a bit of a leak coming from a compression fitting on the end of the TMV. No problem, a quick bit of spannering and oooeeerrr its got a lot worse ! 4 letter words are my favorite !  open some taps and tighten it some more. Cripes there's water spurting everywhere now and I cant stop it because of the amount of compressed air that's pushing. Another shutdown, big mop up and a strip down of the failed comp joint revealed that the ring nut was winding the thread off the main fitting body. Tightening it was just making the spiral of metal, that used to be the male thread, longer.
This chunk of metal is part of the TMV and converts the flush face fitting of the main body of the TMV, to a 22mm comp fitting. I did not have a spare and its a 6 months ago flea bay purchase. So I cut the fitting back to undamaged metal and polished the end flat, PTFE packed and spannered the fitting up about 6 times until I could feel some resistance from the PTFE pack ( cos the olive wasn't going to seat terribly well on a hand finished cut end ) and so far its holding up. Phew.

[noelsquibb]

dissolving HT armafex ?

[noelsquibb]

celloment under GRP

[noelsquibb]

air bleed at back of WBS
bed legs
chimbley

[noelsquibb]

DHW diverted to heatstore, then into or past combi boiler -

[noelsquibb]

blimey !

I just got promoted 

[desperate]

Noel

Your underground fementation tank looks yummy, is it a traditional recipe? Anyone fancy a pint?

Desperate

[noelsquibb]

Yeah Desp that fermentation is a rare vintage. Reckon it would dissolve a plastic container.
I opened up the heatstore today and things were not looking quite so rosy.
Will be reported on soon.

In the meantime tonights episode brings back your words   - Think Desp Think ....


Plummin gets a bit exciting -

So, finally the integrated alternative heating system was deemed to be ready.
All circuits in place, apart from final connections for heat extraction from the heatstore to the CH circuit.
All pressure tested, flushed, water circulated using the two pumps, air bled out and even a can of inhibitor injected.

Theres no more excuses and its the day the fire gets lit. Wife away for the day too.

Topped up the heatstore, checked the pressure in the heating circuits, had another cup of coffee ...

Really there are no more excuses, light the fire Noel.

Lots of smoke coming out of places it shouldn't, rolled up newspaper struggling to burn, wassgoingon ?
Can only be the chimney. I knew it needed a bit of a sweep ( not been swept since we built the house in '02 )
but they reckon you can burn the Isokern liner to keep it clean and we had a fine chimney fire last Christmas.

Ok, found what looked like enough rods and a big old chimney brush that, with a bit of a trim, would clean a 6" pipe.
Not too bad really until I got to the second last rod, then it got proper difficult.  Ha - breakthrough

Uh- oh,  something's fallen onto the roof and is sliding down the slates.
Probably a bit of loose chimney cowl that got a bit over-hot and semi detached during that chimney fire.

Oooeeerrr...  what's that buzzing noise ?  blimey hornets !
Couldn't shut the fire door, because it had a small part of a 27 ft long rod sticking out, so I shut the door to the rest of the house and opened up all possible windows and doors,  by which time I was sharing the lounge with a couple dozen hornets.
Outside you could see a fairly big group of hornets flying around the chimney and more worryingly, looking for ways through the eaves into the roof space.
The loose bit of chimney cowl had managed to break a slate and smash through the most expensive bit of guttering at a downpipe. More work then.

I am pretty tolerant of hornets, they are not aggressive like wasps or some wild bees. We've got a big new nest turned up in one of the mine sheds and there's probably another one on the big shed by the house, cos you can hear them all the time, just haven't spotted the nest yet.

Anyway, gave the hornets a few minutes to vacate the lounge and went in with wasp spay to deal with any that were injured or confused.
There were quite a few moving in the soot and nest material, as I scooped it out.
Brand new fire too, never been used and already filthy and full of Oh, how I wish it was better.

Ok lets have another go. Yeah, nice fire, good burn, water warming nicely. Got to get it all nice and hot to burn the fancy paint on, so plenty of small wood and air.

Hmm, its getting quite hot and the pumps not cut in yet. Ok, lower the pump starting temp on the fire thermostat. Yup, off she goes. 
Hmm, its all getting rather hot in the control cupboard, wonder if the heats getting to the heatstore ?
Err NO !
Where's it going then ?
Err  NOWHERE
Pressures climbing too !

Gotta move fast. Shut down the fire, wow that's hot and I can hear bubbling...
Get a steel bowl that might have been the dogs bowl and let some water out of the circuit ?

Actually this was a VERY BAD IDEA and really not thought through.

What happens to the boiling point of water at 3 bar, when you lower the pressure ?

Bloody hell, I was blasted out of the control cupboard by masses of steam and hot water bouncing off the dogs bowl as the two safety 'blow off' ' valves kicked open.

My face and neck on the left side felt a bit hot, as did my legs where the water 'n steam got me.
Bloody close thing. No actual harm done, just felt like a bit of light sunburn the following day.

Anyway I ended up with hot water throughout the plumbing circuits, including the solar circuit. The problem was that I also had steam.
Absolutely no idea what was going on, apart from being able to listen to the water boiling in the fire, which had calmed down to a gentle but steady heat.

So I hooked up the garden hose pipe and another hose to the draincock and gradually introduced cold water to both circuits. This caused some orrible noises to emanate from the two circulation pumps but gradually everything quietened down. There was still more heat being generated than was arriving at the heatstore though...

Next day dawns and I've absolutely no idea what went wrong. 
Strategy planning meeting with self, continued until about 11.00 am.

Absolutely no pressure registering in the system. Have we created a leak with our 3 bar high temp test ?
Are the pumps wired correctly ? Have I got the flow direction wrong through the pumps.
One pump removed and stuck in a sink with some water in it, plugged in to the mains and working fine.  Pity.

Could it be an air lock ?
One small drop identified between pump and fire that might not purge, so strip that bit down and install another air bleed point.

Refill / repressure with water from garden hose , bleed, pump to circulate, repeat ...  OK looks like its stable and no more air inside.

The trouble is, the only way I can tell what's happening to the water from the fire is to heat it and see where the heat turns up.
The solar circuit has a flow meter that gives a visible reading.

Ok, just a small fire then ...

Fire stat turned right down, so pump cuts in as soon as warmth is detected.
Getting warmer but the thermostatic diverter valve does not seem to be diverting the hot to the heatstore.
Adjusting it to the lowest temp or the highest temp is a bit inconclusive and there doesn't seem to be any heat getting to the heatstore yet.
Run the pump for the solar circuit and see what happens ?
Yup, that's picking up some of the very hot water and taking it to the heatstore. The thermostatic diverter valve at the heatstore seems to be working too.

With the fire running fairly gently, I could just about balance the fire output with both pumps running, so all the heat is going the long way round, going through 6m of 15mm and 18m of 10mm pipe to get to the heatstore.

At least I've got something to go with now.
Either something is wrong with a thermostatic diverter valve, or I've got a stuck non return valve ( the arrow is deffo pointing in the right direction )  in a rather difficult location.

I suppose something as complex as the monster I've created was never going to be 100% right from the first firing but I was rather hoping it would have been a bit less exciting that this.

More soon 

pics -

hornets nest and soot in new WBS

[noelsquibb]

final configuration in control cupboard

and

look, its just a little cupboard ...