Renewable Energy: Wood Gasification (Log) Boiler Experience?

181 to 210 of 409

- CommentAuthormky
- CommentTimeSep 30th 2008
hello everyone
does anyone know if the orlan gasification boilers are the same as the vigas sold here in the uk ? and does anyone have any experience of dealing with kolty in poland, and also would anyone know if i could get vat back, or how i could buy one vat free and then sort the vat at this end i should be ableto reclaim some or all as we will be using some hot water in the farm dairy.
- CommentAuthorowlman
- CommentTimeSep 30th 2008
hi mky,
If you are a farmer I assume you are VAT registered. Then you should be able to import VAT free from within the EU. You can then deal with the VAT on your normal quarterly return. Ask the supplier, I've never found it a problem. VAT on wood boilers is only 5%. If some of the usage is for your business then your accountant should be able to advise what portion, if any could be 0% rated.

mike.
- CommentAuthorflowerscroft
- CommentTimeSep 30th 2008
Ah the 5% VAT issue!! When we had our boiler installed, we were told that we could only get 5% VAT on the boiler if supplied and installed. Is that correct?

We had a friend who was a plumber fit ours so paid 17.5% VAT on the direct sale of a boiler only. We still don't seem to get an answer as to which is correct..........
- CommentAuthoradwindrum
- CommentTimeSep 30th 2008
On the inhibitor front, some delayed thoughts came to mind....doesnt it stop "knocking" and provide some "lubrication" in the system? Also it sounds as though there are some very confident plumbers out there fitting sealed systems with no leaks, but another potential entrance of fresh water is through the overheating/cooling coil system - mines a honeywell thing. I dont often overheat the system but I do push the boiler up to 90 degrees most of the time and I do forget and get preoccupied thus allowing it to overheat before I kick the central heating system in to cool it down. It seems a shame to spend thousands on some kit and then have it rot out early. Does anyone know for sure if heating water to 90 degrees "boils" off the oxygen?
- CommentAuthorbillt
- CommentTimeOct 1st 2008
AIUI the cooling loop is completely separate from the system water. It passes cold water through the structure of the boiler but doesn't mix it with the normal heat transfer water so it won't introduce fresh oxygen to your system.
- CommentAuthorowlman
- CommentTimeOct 1st 2008
hi all,
I too have been doing a bit of research on the additives issue. It seems the recommended solution is 1% by volume although that figure is calculated using the "normal" model of central heating, i.e. comparatively small volume of water and lots of water to metal contact. With an accumulator of course the majority of water doesn't come into contact with metal therefore no corrosion. so its safe to reduce any concentration to 0.5% by volume, could be quite a saving. as for "boiling off" oxygen, I don't know. I think its OK to run the system and sample the water, after a couple of months and then use the old test of the water in the jam jar with a steel nail and watch for any corrosion.

for flowerscroft:
from my research, It seems the 5% is only paid to the "end user" ie. you. Your plumber, if he's VAT registered would pay the supplier the full 17.5% and then make the neccessary adjustment to 5% on his invoice to you. he of course would claim all the VAT from the original supplier invoice, and include your reduced invoice in his payment to the Customs. "end result the Revenue get 5%". If he's not VAT registered you've got a problem. My crib with the whole VAT shebang is that there is no mention of the rest of the gubbins; accumulator, valves, insulation , etc etc., which as we all know are required to produce the efficient , green, heating system. Seems someone has to pay for Tonys war and Gordons financial mismanagement..... aagh don't get me started.

mike.
- CommentAuthorflowerscroft
- CommentTimeOct 1st 2008
Thanks Mike,

Sorry to get you started. You're damn right on the tank, valves etc. Madness!!

So am I correct to say that buying direct from manufacturer would have to be at 17.5% (as an end user)?

Thanks again
- CommentAuthorowlman
- CommentTimeOct 1st 2008
hi flowerscroft,
In practice yes, unless you can find a wilco manufacturer, my experience is that manufacturers and/or UK importers/suppliers are not willing to play ball either through ignorance or just can't be bothered. They would rather leave the VAT manipulation to the middleman ,- the fitter. Similarly, this is where the grant system, in my opinion falls down, one has to go to the approved, manufacturer,supplier and fitter to qualify. Each of whom demand their pound of flesh, and the total end price to the "punter" negates the grant. Here I go again,railling agin' the bureaucrats and tossers who dream up the rules. Law of unintended consequence, I believe its called.

mike,
- CommentAuthormjn
- CommentTimeOct 3rd 2008
I'm just firing up my Atmos 15 kw log for thr first time - these are nervous minutes after 18 month of installation.

Can anyone out there with an Atmos or other boiler calm my current questions -

What How long does it take to get the boiler up to temp - I'm at 50 degrees after an hour and climbing very slowly.
What flue gas temperature does it normally run at? - I'm holding steady at 70 degrees.

My one does not have a ventalator fan and I'm worried I do'nt have enough draft to get this thing going fully.

Thanks
- CommentAuthorGraham T
- CommentTimeOct 6th 2008
VAT Notice 708/6 (aug 2006) states:-

"What qualifies for the lower rates of VAT?
Installation of any of the following qualifies for the lower rate of VAT:

controls for central heating and hot water systems
draught insulation (eg around windows and doors)
insulation on walls, floors, ceilings, lofts, etc
solar panels
wind turbines
water turbines
ground-source heat pumps
air-source heat pumps
micro combined heat and power units
wood-fuelled boilers

You can only get these lower rates if the energy saving materials are actually installed, and the work is done on your home. You'll be charged the lower rate on the installation work itself as well as the materials.

You'll also get the lower rate on any necessary extra work that needs to be done as part of the installation - this doesn't apply if you're having them installed as part of a larger project such as a new roof or building an extension. "

To my mind the associated gubbins, accumulator, valves, pump etc come within the above remit and are therefore 5% VAT.

If you need further confirmation you can ring the Revenue & Customs National Advice Service on 0845 010 9000 to get an enquiry reference and opinion.

HTH.

Graham
- CommentAuthorhelen@carms
- CommentTimeOct 8th 2008
If you don't fancy a phone call you can find it on

http://customs.hmrc.gov.uk/channelsPortalWebApp/channelsPortalWebApp.portal?_nfpb=true&_pageLabel=pageLibrary_PublicNoticesAndInfoSheets&propertyType=document&columns=1&id=HMCE_CL_000514#P70_4298

That handy one line link.....

Helen
- CommentAuthorBorderMan
- CommentTimeOct 9th 2008 edited
My system (Vigas 40s + 2200litre buffer) was commissioned yesterday and it now up and running, very impressive it is too. It was supplied and installed by these guys:

http://www.renewable-energy-store.com/ (boiler package option 5 on their site).

Early experience suggests that one full load (about a wheelbarrow full of logs) is enough to keep my house warm all day. So far, I've been starting the burn cycle early evening with he boiler running for around 5 hours or maybe more. ~As the heating is on in the house and the water is circulating around the heatng circuit we get the benfit of the boosted temperature, but there's enough heat coming out of the boiler to heat the house and still charge the buffer tank. We also use this time to heat the DHW (we have a 300 litre Heatae Sadia Megaflow).

The heating goes off at 10pm and back on again at 5am and there's more than enough heat to keep the heating on contantly and effectivly until we re-light the boiler in the early evening and start the cycle again.

Ed.
- CommentAuthorboilerman
- CommentTimeOct 14th 2008
hi ed,have you used a direct or indirect megaflow?
just a little curious to find out if a direct cylinder works well with the wood boiler.
i have a 160litre mainsflow cyl with a 30litre/min flow rate running off my oil boiler and have a fantastic
supply of continuous hot water.
hope to buy an 25wk orlan super this month from Kotly and just wanted to know has anyone had any experiance
of having fitted a direct cylinder to a system using a gasification boiler,obviously been fed from the accumulator tank and being flow temp regulated.

baz
- CommentAuthorowlman
- CommentTimeOct 15th 2008
hi baz,
The components in a wood gasification system, ie. boiler, accumulator etc. are usually all made of mild steel and are therefore unsuitable for direct use,- build up of rust etc. If you want to retain your "airing cupboard" cylinder, why not change it for an indirect one, and then use your thermal stored water to heat it via the coil within that cylinder. Alternatively have a rising water main coil in the thermal store, or a plate heat exchanger, and enjoy mains pressure hot water.

mike
- CommentAuthorScotch
- CommentTimeOct 15th 2008
Hi BorderMan,
Do you have a house thermostat that switches off the central heating circulation pump when desired temperature is reached, or does the circulation pump run constantly during the period you have set the heating to come on?

The reason I ask is, my installer has said that when using a house thermostat you will have relatively cool return water going back into the thermal store when the house thermostat switches the ciculation pump back on? He reckons you loose less heat in the thermal store by keeping the circulation pump on constantly, i.e. the system returns warmer water to the thermal store thus keeping it warmer for longer?

Can you also tell me why you chose to use a seperate DHW system rather than coil in the thermal store to provide mains pressure hot water?

Thanks
Scotch
- CommentAuthorMike (Up North)
- CommentTimeOct 15th 2008
Hi, Dont get the rirect term mixed up. The accumulator is direct as compared to indirect heated with a coil. But a direct DHW clynder would have only an immersion element in it. Thus a DHW with the usual coil is heated in-directly. But a bathroom towel rad if made of brass can be used direct in that the heated potable water (from either the dierct or indirect cylinder) passes through it. Thus the towel rail is on the drinking water supply.
Cheers, Mike up North

PS someone else can have #200
- CommentAuthorboilerman
- CommentTimeOct 16th 2008
hi mike/owlman

i think you have me mixed up.i have a mainsflow cyl as described.ie with a multi minibore heat exchange mains coil inside a direct cyl.i was directing the question to ED/borderman about the type of megaflow cyl that he set up with his wood boiler.
- CommentAuthorBorderMan
- CommentTimeOct 16th 2008 edited
Posted By: boilermanhi ed,have you used a direct or indirect megaflow?

Hi Baz... it's an indirect one (i.e. it has a heat exchanger coil in it that carries the central heating water to supply the heat - it also has a backup immersion heater which I think I've only ever used once or twice). This DHW tank has been been giving me stirling service with my oil fired systm for the past few years and works very well indeed in the new set-up.

If I was starting from scratch, I'd have installed a plate heat exchanger and I seriuosly considered it, especially as I have very good water pressure here, however the Megaflow is just a little short of three years old and wasn't exactly cheap, so I decied to save some Â£Â£s.

Ed.
- CommentAuthorBorderMan
- CommentTimeOct 16th 2008 edited
Posted By: ScotchHi BorderMan,
Do you have a house thermostat that switches off the central heating circulation pump when desired temperature is reached,

Hi Scotch,

No, I have no house or room thermostats, just thermostatic valves on (most of) my radiators so the the circulating pump runs contantly during the whole heating period.

The way my heating is set up, I actually have two independently controlled circulating pumps (a twin pump Grundfos PumpPlan), one driving the the radiator circuit and one driving the Megaflow. This means I can control each separately from the timer so I can charge the Megaflow when the buffer tank water is at it's hottest (when the gasification is at full blast). The Megaflow's heat exchanger is very efficient so I can heat the whole tank up to it's target temperature of 65C very quickly and when the target temperature is reached, the system turns off the flow/pump on that circuit.

The decision to stay with the hot water cylender was purely economic, it works well, it's not old and I saved myself a chunk of cash on a new heat exchanger.

Ed.
- CommentAuthorowlman
- CommentTimeOct 17th 2008
hi BorderMan/Ed,

Like you, I pondered long and hard about the domestic hot water side of the system. Whether or not to use the existing indirect cylinder setup and simply re-plumb it to suit the thermal store as you have done,- which seems to be working a treat. After much deliberation, I decided on the other route, that of a plate heat exchanger. It is the more expensive option, as you rightly said. I paid just over 1000 euros although that was cheap compared to other quotes from UK sources. Its a nice bit of kit though, all stainless. The upside has been the dismantling of all the airing cupboard and the spaghetti pipework, soon to be a small cloakroom, and the taking out of the loft cold water storage. Its now direct rising mains supply ,hot and cold, and relatively short pipe runs to taps. When the dust has settled I'm hoping for a nice little bit of back pocket cash from the scrap copper and brass, from all the old stuff. It may soften the blow of the depleted state of my bank balance.

regards, mike
- CommentAuthorhelen@carms
- CommentTimeOct 17th 2008
Help!

Hi everyone,
I am having a log gasificaiton system installed, am buying the boiler (atmos 25kW)/ accumulator,a nd Laddomat from Sundance , and am having a local installalor put the whole thing in. The price seems to be escalating all the time, and now I am not sure I can afford to ahve the thing installed for a couple of months (meanwhile my oil system is slightly broken and we are cold!)

The price has escalated because I can't have a stainless steel flue - becuase of planning and height of the flue -my house is on a hill, and the boiler will be below ground level of the main house. )So I have to have a volcanic flue (which may cost up to Â£2000.

The breakdown of the system looks like this (for costs)
Boiler / accumulator/ controller 3780
Installion of the boiler etc 1000
Extra thermal store tank in main house (3 coil gledhill?) 1000
Connection of boiler system to tank in main house,
including fitting of cold water feed tank in loft : labour 850
MAterials for above 2300
Removal radiators / fitting values 450
Electrical work , for outhouse (pure estimate) 250
refitting the outhouse for system (estimate) 800
volcanic flue (estimate) 2000

The work is going to take about ten days, which means labour is coming in at around Â£200/day, so total cost being around Â£12,000

Now, the bit that horrifies me, is the Â£2300 for connection of the large accumulator to the smaller internal thermal store. We want that because we want to run the shower off it at mains pressure, and also we plan to fit a solar water panel next year, and then the plumbing will be ready for that.

The installor tells me the reason that is so expensive is that copper piping is expensive, and so, as he needs to run two pipes from the below ground level , one up to the tank, and one up to the cold water tank in the loft.
Now, am not a plumber or builder so please excuse my ignorance, if we have a old water tank in the loft, that means we have an vented system.

The diagrams that Borderman kindly posted, show an expansion tank linked to the accumulator. Does this mean then that the system is unvented? I thought through reading everything that most people's systems are unvented, and I then thought if we have an unvented system with an expansion tank, then yes, I would have the cost of the expansion tank, but I would not be incurring such horrendous costs of the piping to the cold water feed tank in the loft.

If anyone could shed some light (be nice to poor scratchy head lady) ; I would be hugely grateful.

And if anyone knows someone in West Wales who could do me a volcanic flue, as the man I am phoning is never in, I would be grateful.
Cheers
Helen
- CommentAuthorowlman
- CommentTimeOct 17th 2008
hi helen,
I assume from your description that the Gledhill 3 coil tank is pressurised ?? (mains pressure showers), although I'm not familiar with Gledhill products . And the expansion tank as you say seems to be part of an open vented boiler and accumulator system. Had you not thought of buying an accumulator with a water heating coil attatched to your cold mains, inside it, and dispensing with the Gledhill altogether. If you then have a pressurised system you can do away with the long and expensive pipe runs and consequently the labour. The domestic hot water pipe runs from that water heating coil are then blended; 50 to 60 degrees (your preference) and the pipe runs can be in plastic., save a bit more money.
As for the flue can't you direct it up an existing chimney? Drop something like a 6" twinwall flexible stainless liner down it, insulate around with vermiculite, cap it off, and then you only have the bottom end connection to the boiler to worry about.

mike.
- CommentAuthorhelen@carms
- CommentTimeOct 17th 2008
Thanks Mike
I will chat this over with my installer - but it sounds sensible to me. I think he said that if we wanted a mains pressure shower we had to have the extra tank.
I am still a little confused about the vented / unvented stuff though. I thought the system Borderman described was unvented!

With the flue, I had wondered if we could do that. The closest chimney is in the living room, and to get to that the flue from the boiler would have to go under the house horizontally and the up through the living room (we have about 3 feet storage space under the house.) I am not sure that that will work, but it will certainly be worth asking the flue man, - he's coming around the weekend.
- CommentAuthorowlman
- CommentTimeOct 18th 2008
hi helen,
It's sometimes a bit difficult getting some plumbers to understand the concept of thermal storage, or that a large, 2000/3000 Litre system as a whole can be pressurised/unvented, or indeed that accumulators come in many different configurations;- plain empty tanks,- with solar coils,- with domestic water heating coils,- with coils for a second heat source, back boil;er for instance; or any combination thereof. In principle keep it simple, heat the water in the accumulator, (wood gas boiler, etc). then think of all the other uses, as circuits "off" or "through" that heat store, and keep pipe runs as short as possible.
Whilst utilising that heat source, and directing it through another coil inside another tank/cylinder is a possibility, and it will work. in practice you are losing efficiency the more steps and links you put in the system. I know, wood is comparatively cheap, and there may be other reasons why you want the second cylinder, wanting to retain your aring cupboard for instance, or the layout of your property may not be conducive to a simplified system.Cost may also be a factor. Each case is different and there is no one right way. Simple usually is the best though, and there is some pleasure in removing all that superfluous stuff, loft expansion tanks, and cold water storage, convol;uted pipe runs etc..
Regarding the flue, horizontal runs do present problems, and if you read approved document"J" of building regs.they are a no/no, for "normal" solid fuel fires etc. Broadly speaking though it all boils down to flue draft, and that can be "helped" with all sorts of devices. I'm not sure if, for instance, the fitting of a chimney top fan, or a fan assisted wood boiler in any way alters those regulations. It's often the case that building regs. take time to catch up with developments, like log gasification boilers, and whilst we all regard them as solid fuel and, indeed they are, in the simple context, however, they could be construed as gas boilers because of their operation, of gasifying the wood first. In the case of a "forced draught" gas boiler, usually balanced flue, admittedly, horizontal runs appear to be permitted. Why not do a sketch and present it to someone like Selkirk or Rite-Vent or other independent manufacturers, they are quite helpful, and may have a solutuion. Accentuate the positive, argue the toss, that your "fan assisted logwood gasification boiler" isn't solid fuel in the conventional sense and who knows you may get a surprise, they may relent and let you do it. Have a word with your local building inspector.

regards, mike
- CommentAuthorhelen@carms
- CommentTimeOct 19th 2008
Thanks Mike
That's a great help. To be fair to the plumber I am not sure he has installed a lot of these systems, so we are all on a learning curve!
Cheers
Helen
- CommentAuthorMike (Up North)
- CommentTimeOct 20th 2008
Hi,
The thermal accumulator can be sealed or unsealed. Either way the water passing through the boiler is the same water as in the accumulator and in the radiators. Sealed will require a thermal expansion vessel that accommodates the increase in volume when the primary water is heated. This could be 100+ lit so will increase the price. For unsealed a feed & expansion tank is used (usually in the loft). When sealed all of the system is at pressure and sealed. This water can be fed to the Gledhill (direct supply) to store up some heat for DHW, but as the Gledhill is made of copper (acc would be steel) cannot be sealed at pressure, thus the boiler / acc / rads must be unsealed. BUT, if they must be sealed then the Gledhill must remain unsealed so would need to be heated by its own internal coil (in-direct supply).
Your potable DHW can be heated in a normal cylinder with a coil (which is vented or un-vented), this coil has the boiler primary water it so it (the coil) can be sealed or unsealed as per above. For the potable side the term vented or un-vented means that hot potable water is stored for use at mains pressure (un-vented) and would be a stainless or glass lined cylinder (its potable water) or at the pressure from another open loft tank (50 gal) as vented, if made of copper this would be to a max 1 bar â€“ 10 meters. A DHW thermal store such as the Gledhill turns that the other way around so instead of storing potable water it stores the primary water it then heats the DHW on demand thought the coil exchanger. Because the coil exchanger is pipe (not a tank or vessel) its good for much more pressure so this will be refered to a mains or un-vented system. But that just the potable side, the Gledhill cylinder would still I think be copper and thus have to be un-sealed (as above) or indirectly fed (from a sealed system).
So if you have a boiler & thermal accumulator (store) you could use either another store or a conventional cylinder for DHW.
You could as suggested use a DHW coil within the thermal accumulator or even an external plate exchanger set up, but if you donâ€™t want to do that, then pumping up a separate DHW supply (of any sort) does means the accumulator can deal with heating all day long without any diversions.

Hope this helps

Cheers, Mike up North
- CommentAuthorJohn B Humberside
- CommentTimeOct 20th 2008
Hi Mike up North
From your comments you sound a very knowledgable guy, I am considering a 25kw wood boiler heating system, the boiler would be installed within a building some 20 mts from my house, is the buffer tank (1500l) better installed within the same building or better installed adjecent to the house.

Regards

John B Humberside
- CommentAuthorMike (Up North)
- CommentTimeOct 21st 2008
Hi, the boiler and accumulator should be together. This is to allow an easy flow between them, use big pipes 28mm, no sharp bends etc, this allows entrained air to release and when the fire is out or there is a power cut the any heat can flow naturally to the top of the accumulator. In a power cut the fire will not go out. Even when out there will be a build up of residual heat within the boiler. The highly insulated pipes can then run the primary water from the acc to the house. Dont forget about DHW if this is prepared at the acc then it to will have to be supplied to the house, or you could use the primary water at the house to prepare DHW in a normal cylinder.
Cheers, Mike up North
- CommentAuthorJohn B Humberside
- CommentTimeOct 21st 2008
Thanks for the advice Mike up North

For the 20mt pipe run from the acc to the house would you use 25od or 32od twin Pex pipe

Regards

John B Humberside
- CommentAuthorcatlane
- CommentTimeOct 21st 2008
Hi Helen,

I suspect I have a fairly similar setup to what is proposed for you, ie a 20kW Atmos, 1200L accumulator, 200L Gledhill thermal store, and some solar too. The Atmos, accumulator, pellet store are adjacent to the house, and there is a district piping connection into the house. I am not a heating engineer, and I cannot talk fluidly about the vented/unvented thing, but this is my understanding. The Atmos itself is vented to the outside of the building it is housed in, and there is a cooling loop that can push fresh water into it. It definitely vents, as we did have a temporary overheat/venting issue as the Laddomat and boiler stats were wired wrong. The Gledhill is vented, and there is an F&E tank in the loft. There are solar, solid fuel (Rayburn), and "Atmos" connections to the Gledhill. Mains pressure showers should not be a problem, as the Gledhill is a mains pressure thermal store, and does not depend on the Atmos connection for this. If we nned to boost the Gledhill then we just put the controller on for an hour, which gets most of the tank to 70 degrees. We have a very long copper run between Accumulator and Gledhill, but the Atmos is on the gable end of the house, and the DHW tank is roughly in the middle. I suspect that solar is much better on a 200L thermal store than a 1200L accumulator.

I cannot talk costs, but ours was masked by the Rayburn, and a whole load of internal replumbing and zoning. Our installer is now in North Wales, and after jousting with our system he has a fairly deep understanding of some of the challanges. I could give you his number if you want.

The system has been maddening at times, but the teething troubles are largely sorted (Thanks Mike(up North), and I am chuffed with it now. I would recommend it.

David

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Renewable Energy: Wood Gasification (Log) Boiler Experience?