[Closed] the further tales of pellet fired boilers

What the hell do you do for a job? You seem to have loads of time to be doing these proje ts around the house and plenty of spare cash to do them 😀

If I told you, Id have to kill you...by boring you to death 😉

But Monday's one of my fettlin' days.

Awesome - and as a bonus prize you get to build a new log store! Win - Win 8)

Doing something a bit different mcm:
[img] [/img]

I reckon I can store about 13m3 against my yard wall to season.

Whoah. Be careful with pellets blown that distance. You can damage the pellets. Usually reckon on 25m at a push best kept to 20m. Have you got a strike mat installed?

strike mat installed

Easy to sort out unless there's anything special about it.

The pipe run will be about 20-25m

Nice work stoner as always! My only thought would be do the pellets "run" freely! Are you gonna end up with even distribution to your hopper slots as you blow in??

Cheers wrighty, I asked my delivery guy and he said that they would blow to the far side of the tank without any problem, so the tank would fill from the far end first.

The 30deg pitch of the floor of the tank is based on some experimenting with some pellets and bit of ply. The 4x hatches are evenly spread so that I shoul dbe able to empty over 90% of the tank without having to open the access hatch and rack rake the last few Kgs of pellets.

What would you need to convert from a condensing boiler? What's the running costs? You have me intruiged

Just curious - do you need to vent a lot of dusty air from the hopper?

the one thing I havent yet installed is a 100mm2 vent to one of the panel doors. You can just make out a perspex hatch Ive put in. Ill also put a closeable vent there too for when the tanker is loading.

wors - if you're on mains gas, dont bother. If you're on oil, then it might be a viable option if your boiler is due for replacement sometime soon. Ask Bear, he's the pro installer round here 😉

Lamest thread ever 😆

Stoner you better be a hitman or something interesting for your job

Just curious - do you need to vent a lot of dusty air from the hopper?

THat is potentially a very good point, you may end up with a flammabble/explosive atmosphere in the hopper during filling, and i'd imagine that firing pellets down a tube will generate a fair but of static, is the connector earthed at all?

I'd expect the pipe/tanker to be bonded and earthed, but it wouldn't hurt to earth your connector, and maybe put a blow off panel on the hopper, just in case.

Ahh all good then!! Must have missed your original post about the project! I have had a fair few dealings with silos and such the like. Those fittings for the hoses are never gonna be cheap!!

Stoner, that's an interesting way to store wood.

I've got a notion to build a breezeway between two buildings and line the sides with logs.

I know the folks at Gleneagles in Perthshire. The original Gleneagles. You can just make out on the right their arcaded breezeway which links the other half of the house. They store their logs against the wall perhaps 2 feet deep so the air can get to them. The wall has a doorway through into their walled garden.

I figure if breezeway were lined with logs they'd be dried from both sides and it would be both functional and decorative.

[img] [/img]

[img] [/img]

sobriety, Im aware of the combustion issue.
There's stuff here on page 8

and here s35

The fittings are forged aluminium and only contact the pellets for about 3". The delivery pipe is dead straight from the tanker to the tank fitting and any dust build up will vent to the outside and disperse/settle out over the neighbour's washingline 😉

mcm - in theory I could go for 2x deep logs against the wall and still get enough air flow. Id have to be much more careful about cutting all my logs to the same length though 🙂

Bear, how "yielding" does the impact baffle need to be? Play mat foam or softer, like a hanging cloth?

Looks good that stoner. Have you looked into using olive stones in the pellet boiler?
I was reading about olive bars made from olive waste, for use in multifuel stoves, but it was mentioned that olive stones could be used as a direct alternative to pellets. Sounds interesting.

Stoner - you NEED two Storz couplings, one to deliver the other at high level to suck out the dust. All the tankers I know are two hosed. And yes rubber mat near the back to protect pellets again.

Day 1 done, four more to go! was early start, 4.45 alarm call was not funny!

Last summer I build a wall of logs ate the end of my garden... They dried up a treat... tried to insert a pic but failed. Last year the wall was one row of 10inch logs... this year I want to try 2 rows... hope it will work.

Sorry for the hijack btw.

And what's the price difference between loose and 10kg bagged pellets?

geoff - very little normally..

Bear - I checked with my delivery man and he says I can use a vent rather than a return extract.

Day 1 done, four more to go! was early start, 4.45 alarm call was not funny!

you're not commuting are you?!?! 😯

this week is it? Id forgotten. Very jealous, have a good one. Any juicy knowledge to pass on already? This is the place to do it. Emsz is beside herself with interest!

And what's the price difference between loose and 10kg bagged pellets?

about 10% saving. So for me about £50 a load. Not a huge number, but it was more the man-handling of the 200x bags twice and the plastic waste that annoyed me, rather than any higher cost.

Olive stones you say?
Bet the smoke smells ace!

geoff:
[i][url= http://pellets-wood.com/high-quality-olive-stone-with-high-combustion-powe-o241.html ]The Specification of the Product are: * 1 kg Olive Stone have Combustion Power 4.500 Calories. * 23% Humidity * 80 gr Ashes after Combustion of 1 kg Olive Stone * 0% Sulphup At the Present I have not Price for any CIF, but the EX-Factory (Local Price its Sold) is about 150 EUROS per 1.000 Kg The Product is Available in Big Bags of 1.000 Kg Each. Minimum Order 20.000 Kg Delivery Ability = 200-300 ton/month[/url][/i]

WOW!
Thats about twice the energy density as wood. The local price being about half the price of here too, but I dont imagine delivered loads would be that cheap to the UK.

If it really is around 10kW/Kg then it could make sense at up to £500 a ton.

[img] [/img]

Any excuse eh! 😉

How is the solar contributing , Stoner? It's nice and sunny this week so the solar hot water heater is providing for all our needs a bit further south.

I turned my boiler off on friday as the suns been out and the solar's been fine. I keep an eye on it. Its a tricky balance at the moment, because the boiler wants to fire in the morning when the tank has 56degs water in it, but I know a sunny day will top it up fine. But if it's 56degs in the evening then I ought to let the boiler fire up to top up for the evening showers/baths.

I need to find a way of adding a time/season controller that stops the boiler firing, without turning it off (turning off can be a problem)

A few weeks ago in another sunny spell, Id left the solar pump set to pos 1 (instead of 3, doh!), and it boiled the solar water making a right mess 🙂 fortunately I needed to drain it down anyway to fit some service valves so I could add some auto air vents to the circuit. Now it's all running fine, but I do need to get some more solar fluid.

EDIT - bit post that Ed, proper roofing and all!

No way. 3 hour drive pretty much. Staying in a nice village called Corsham.
Today was all about building regs. More about boilers for next 4 days. And you know as much as I do!
I just need to be qualified because it is my business. That is why I have a interest in working with wind hager and in working the wind hager way because they have a proven record and a great product. It comes at a price though.
Hence my interest in your system as something different. Ecobuild was ok but struggle to find competitors to them ok okofen and frolein for instance.

and in working the wind hager way because they have a proven record and a great product

marketing man, Go! 😉

My neighbour has an Okofen.
If you came up here, youd have two very interesting systems to check out! Bring bike clothes.

I missed ecobuild this year. No great loss. I found there were too many "expensive" brands last year. Not enough yoghut knitting.

(so rubber play mats are OK you reckon? Bit of gripfill, stick em up kind of thing? I would have thought a hanging sheet would do the job a bit better. Wonder if theres a reason they dont use them?)

That's hotter water than we're getting. Very encouraging as we're only just past the equinox.

Has it got okofen written on it? Suspect not! How far from Chippenham are you?
No real marketing there are lots out there most will work fine. Level of controls will differ.
The one thing that I do know is sizing boiler is very important. Can't do the typical plumbers trick of find boiler size and add 50% as you run the risk of short cycling. If you use buffer or store sizing that very important too. I'm learning and think I have chosen a good company to help me so only fair I reward them too! Although in fairness they are putting work my way too.
Not all my customers will have Windhager money so need to look for alternatives otherwise may lose some of them.

Has it got okofen written on it? Suspect not!

How so? Pretty sure it has okofen (umlauts n all) on it.
Its like a bloody space station.

Id be interested to find a brand thats cheaper than windhager/okofen, but has a bit more automation than mine (I love mine, but if I want to advise people Im not sure mine will suit more than 1 in 10 of them)

Think they are sold nder a different name in the uk.
Whereas I can get a whager system to fit everyone........

nope, proper okofen.
comes with a masters degree.

If you had a Windhager your store controls and solar would talk to each other and work in harmony!

id also be skint 😉
Id also not be nearly as enthusiastic about his stuff. Being so far removed from the thinking is great for a quiet life, but no fun if you are interested in the whole process.

Skint I can see removed from the process I'm not so sure about. But if you were doing it commercially then the tinkering you have to do would bankrupt me!

Ecobuild - I'd hate to be in solar PV right now - at least 50 companies all showing near-as-dammit the same things. Not nearly enough interesting things but worth it to 'place myself' in that world. I thought SustainabilityLive at the NEC had more things of interest to the realist.

Stoner - Member
and another thanks to MrOvershoot for the tips on the Storz Couplings. The websites out there are useless for any guidance on how to install them.

Bloody expensive bits though - £150.

Glad to see you have it sorted, Yep they are a bit spendy but as long as you don't do like our tanker drivers and smash them into walls they will last.

Re the dust, what is the moisture level of the pellet dust & what Kst is quoted?
Static is not necessarily a problem as even the industry I work in where flour dust has a higher Kst than Propane/Butane its not possible to generate enough J of energy from static to ignite flour.

Though bear in mind wood & paper account for the largest number of explosions in UK industries

Also bear in mind how much this store has cost you and how much the pellets inside it will have cost. Much more than another store coupling...

wood pellets are nominally around 5%-10% moisture.
They dont have a quoted Kst figure as "dust" is not their normal form, in fact the ones I use (Verdo, highly recommend them Bear) [url= http://www.sciencedirect.com/science/article/pii/S0961953406001024 ]have a mechanical durability above 97.5%. [/url]

But most wood/paper fires are not from static sources are they?

It's bloody dusty when they blow them believe me!

Great stuff, Stoner.

I have some rubber matting from a stable block you can have, if you are interested? I'm just south of Monmouth, so if you are passing it may be worth collecting?
Hth
Marko

cheers Marko - I know that stuff (S-i-L uses it) but I think it's a bit to stiff. I reckon something with a bit more give is needed. Trying to think why a hanging fabric wouldnt do it....

Just picked up a flymesh slatted vent to fit later to allow air out when the pellets are being pumped in.

One thing I learnt today was don't go climbing in your pellet store especially for 4 weeks after delivery

ha. Used to love playing in the corn stores...

When I first started working on the farm, I asked why the access hatches on the top of the grain silos were padlocked. The gaffer said it wasnt for when it was full of wheat of barley, but when full of linseed. If you fell in, you sank to the bottom and no doggy paddle or breast stroke would keep you up.

Not for that reason although it is a good one. Apparently they can release carbon monoxide and there has been two fatalities in northern island I believe

http://www.hsa.ie/eng/Topics/Safety_Alerts/Wood_Pellet_Feed_Hoppers_Tanks_.html

Copied from their version of the HSE

the atmosphere inside can become oxygen depleted

typical HSE, no info on how the phenomenon occurs.

But interesting to know.
Might be worth putting a gravity vent in for CO

Because they don't actually know why the build up occurs but it does and I assume it has done on other occasions where they have measured it.
The line of thinking is to do with friction and heat build up causing the pellets to release the gas. Think of the pellets being fired down a hose and also moving about in delivery tanker. Have you got a co alarm in your boiler room too as that is a requirement.

a pre Oct-2010 installation, so wasnt a requirement then.
I might get round to picking one up sometime, but the room is well vented and there's even a floor level vent that heavy gases can use.

I might get round to picking one up sometime

< dad mode>

Means you won't. Having recently been at a fatality caused by co poisoning, they are cheap way of saving not just your life but also your families.

< ends dad mode>

The amount you have spent a co alarm is pennies.

😳

OK Dad

fatality caused by co poisoning

Blocked balanced flue on gas combi in a bedroom cupboard?
Bit different from a draughty boiler room...
but point taken.

Question for the pellet boiler types:

How do they compare overall to the log wood boilers made by the likes of HDG? I only ask because I like the idea of minimum processing from tree to fuel that the log boiler brings. I understand the potential reduction in convenience, but if I wanted to really reduce the reliance upon the transport system (and oil) for heating, a log boiler would seem a good answer.

TooTall - Im in the foruntate position of being able to use both pellet and log fuel sources:

[img] [/img]

Pellets burn in the right, logs can be loaded in the chamber to the left.

Logs are slightly less efficient as a fuel source, simply because they are rarely kiln dried down to <10% like pellets. The calorific value of the wood itself is the same though (and strangely enough consistent across tree species too). Normally log burners are less efficient than pellets, but I see the HDG ones are very efficient and match their pellet boiler performance. Bloody ought to make the tea too at £9k+ 😉

You can get similarly sized ones on eBay (also MCS cert) for £2.4k
http://www.ebay.co.uk/itm/280837307602

Geoffj of these 'ere parts was also thinking along the lines of fuel independance and I think went for a slightly different approach matching a stove back boiler with a thermal store via a load charger.

You'd have to be pretty committed to go for log boiler as a your main energy source, as you would have no automated "call for" heat option (unless you went for an electric immersion heater in your tank, bad mmmkay), you'd have to keep an eye on your water temps and go and light a fire, or stoke an existing one as and when necc. Might be a pain for your wife, for example, if you were away for a few days.

It would operate better as an augmentation to say an existing gas or oil boiler that you could fall back on for convenience. Like geoff's.

And a thermal store with a solar thermal array would be a sensible addition too.

As for "convenience", I quite like making a log fire in the morning. Takes me about 10-15 minutes over my breakfast coffee to get it started, loaded and roaring before I can shut it down and leave it to it's own devices for 3-4 hours. One full burn of good wood should give me about 50kWh of energy according to the manual. Which is enough to do the DHW for the day (if no solar). To cover the UFH too, Id need to re-load the furnace maybe with another one or two loads during the day. (just means throwing a few armfuls of logs in and shutting the vent back to trickle). Then if the heating needs a top up overnight, the pellet boiler is called on to fire up and it will throw another 50kWh in (this is the middle of winter we're talking here. At the moment, we're using around 50-60kWh a day on DHW. When the sun disappears for April, I'll turn the pellet boiler back on and it will deal with the DHW need. Doubt Ill turn the heating back on again though now)

Cheers, Stoner. I'm just looking at things as they cross my path and tucking away the concepts for a year or two. I am planning a new start somewhere else in a year or so and balancing off ideas of resilience against convenience and seeing where that could put my ideas.

I'm off to see a new small biomass plant tomorrow but I doubt I'll have one at home! 😀

There is a log boiler with pellet attached that automatically swaps when log burn finished I believe. It might be an HDG but don't swear by that.
So much stuff out there it is amazing.

Stoner - if stable matting is too heavy, consider the shockpad from an old astroturf. Friend of a colleague has East Grinstead's old pitch(es) and is flogging the stuff on ebay as stable matting. No idea, but might do the job.

Oh, and fascinating stuff all - keep it up.

Try to find old supermarket conveyor belt according to the guy doing the training it is ideal apparently

I found some synthetic mesh material which I've stapled across the back of the tank like a trampoline. I would have thought high density rubber would still be too hard to prevent pellets. breaking.

Seeing the photo of Stoner's boiler above is the first time it's occurred to me to lag the hot water pipes in the understairs cupboard that our combi boiler sits in.

I'll add that to the list.

They shouldn't be blown in at that sort of velocity. The mat should start to curve after a while creating more of a slide effect.

Stoner, Bear,

Interesting analogies on the padlocks on grain silos...can I offer different explanations? I worked at Camgrain for 3 years, silos are damn dangerous places. What Stoner says about linseed is totally true, it's like quicksand given the slipperyness of the grains. I routinely would hand sample outgoing/incoming truck loads for ergot/pests etc when our vacuum sampler would break down, but linseed...not on your nelly.

I have *never* heard of the CO build up theory, and I can't ever recall it featuring in any safety protocol, but I can well believe it. Usually you keep the hatches locked for several reasons. 1 - Pests, 2 - Children/teenagers playing 3 - Explosion risk. Cleaning those silos (upto 5000 ton) out with quick scaffold and yard brushes was damn sketchy work at the best of times, and looking back on it, we must have been mad, but the money was good and the work physical. Respirators are an absolute must.

Also hatches are kept locked because you can get what are called 'grain walls' i.e. if you're drying with aerators grain/barley in a silo, and then run what is called a 'sweep' to say...transfer grains to the dryers, (it's a big auger running around a central point that sucks grain down to a chute) you can get unstable points in the pile that can collapse, i.e. the grain looks solid enough to stand on, but in reality, it's just overly moist and there are hollows underneath that can collapse...

In short, you keep them locked as they can kill, perhaps in a silage silo you may get CO build up, but I'd be surprised in a grain silo unless it was put away very wet indeed.

Anyway, back on topic, this wood boiler stuff is epic! Keep it up 🙂

interesting stuff mrgibbons.

as for the pellet store, it got it's first delivery yesterday.

1700Kg. It could probably take a little more but Id rather not overdo it and have a 20m pipe full of pellets that needed blowing loose somewhere when the tank backs up. Actually 25m of pipe from the gateway to the store.
[img] [/img]
Was dusty as you say, Bear, but since the tank is outdoors it wasnt a problem and a wet rag over the vent caught most of it. A quick sweep up afterwards did the rest.

Got my man to "top up" my neighbours 6+ ton bag with 3tons to the brim. Since my neighbour burns pellets faster than me (smaller solar array and I will be using logs a lot of the time) it means we can get 1.7t and 3t++ delivered each time to make it worth the delivery guys while. I can highly recommend him if you are looking for a delivery guy Bear. Based in Leicestershire and delivers Verdo pellets from the Mill at Andover all over the country.

He has a great wagon. It does have an extract fan as well if your tank has the additional fitting for it.
[img] [/img]

Nice work Stoner - how much per tonne?

[url= http://www.flickr.com/photos/30189432@N00/6925933778/in/photostream ]Here's[/url] our Windhager going in.

[img] [/img]
Berluddy complicated and it took the installer ages to get it sorted, in the end the chap from Windhager had to come up and sort it - I wouldn't be surprised if it was a crossed wire or something. Anyway, now it's working it's fab. We're using about 8 - 10 bags a week depending on the weather, heating and DHW. Agree about the waste and non-recycleable plastic bags which seems all wrong.

One thing that's changed is the separation of the zones in the house. Not sure whether it's because of the mixing system to vary the temps in the rads but there seems to be spill over between zones. One zone covers a part of the house with lots of windows which gets hot when the sun shines - slightly frustrating that the rads get warm in there even when the 'stat says no heating needed. Generally I'm very impressed by how 'clever' the system is. Previously, when the heating was either on or off, cold days were obvious because the house was colder. Now it's sometimes a surprise when you go out and find it's really cold!

May look into sharing loose pellets with locals - we couldn't store more than 1.5 tonnes. Or we might increase our olive consumption 😉

Paul - looks nice, did Paul from Windhager sort you out?

Personally I found the install I have done not too bad, BUT I did go to WIndhager for a day to get an idea of the product, also had to call them a couple of times when instructions weren't quite clear. Other than that it was good fun to install.

And where are you in the country? If my second install comes off am hoping to put together bulk orders for my customers. Have already talked to pellet supplier and he will give them a better price if they can deliver into one area at a time.

Oh, and if you share loose pellets they MUST be kept very dry.

We're in Northumberland and yes, Paul had to come up to sort it.

Initially the problem seemed to be that we only wanted 17.5C on the stats, partly because of the location of the stat and partly because we don't like it too hot. Unfortunately this puts the boiler into 'setback' mode. Took a while to work that out.

This was the first install of the new control system (MES+?) and it's quite different from the older one. W'hag haven't even got a diagnostic module for it yet.

My last bagged delivery was £276/t + VAT = £289/t

I [i]think[/i] Robert mentioned £230/t (+ VAT Im assuming) for bulk delivery but I havent got the invoice yet. So that would be £241.50, or 16% cheaper.

Which is almost exactly 5p/kWh before losses @ 4.8kWh/Kg.
Oil currently c.60p a litre, = 6p/kWh @ 10kWh/L

Woo, and indeed, hoo.

PS, nice windhager paul - after a while the pellet bags will piss you off, and you'll be tinkering with your own store 🙂

We're using about 8 - 10 bags a week

wait till a proper cold spell, you'll be surprised how much fuel is need to keep even a well insulated house warm.

In the really cold period at the end of 2010 with sustained sub zero average temperatures, average energy consumption was in the range of 125-150 kWh a day to maintain 16-18degs in the house (we work from home)
a bag is a round 50kWh, so 2-3 bags a day when it's really parky. This time of year Im using around 1.2 bags a day on average for DHW and a bit of radiators upstairs at the boy's bedtime. [img] [/img]
(ignoring the spikes which are just measurement issues)

Ours is cheaper though - £220/t 🙂

Noticed a big difference this last week (10+ bags) compared with the week before (<8 bags)

PS Interestingly, my SAP suggests a DER of 28,000 kWh pa for Heating and DHW. My TER is 31,000 kWh pa, so indicates 10% below target, which isnt that good, but OK I think. At 232 m2, that's about 120 kWh/m2/a where a "typical" house is around 200 kWh/m2/a. So 40% saving on a "typical" detached house, and a further 16% saving on the cost of oil since at 5p/kWh for pellets, thats £1,400 a year, (£250 ish less than for oil)

or to put another way, £1,400 a year at 6p/kWh and 200kWh/m2/pa would maintain a house of only 116m2 compared to our 232m2.

Maths. Love it.

£220/t

bastard.

is that w or w/o VAT?

w

We need to run at least a year to get sense of it. It's only been working properly for about 8 weeks and we've used about a tonne since then. We used to use 2000+ litres of oil in a year. Except last year but we were cold a used electric for the DHW.

Do you get different amounts of energy out of different batches of wood or is it fairly consistent (assuming same moisture content)?

wait till a proper cold spell, you'll be surprised how much fuel is need to keep even a well insulated house warm.

In the really cold period at the end of 2010 with sustained sub zero average temperatures, average energy consumption was in the range of 125-150 kWh a day to maintain 16-18degs in the house (we work from home)

Not wishing to be funny, Stoner, but those figures say your house isn't well insulated. A passive house project in Alsace has no heating system at all and a year low of 15°C was recorded by the occupiers. That's in a region colder than the UK though it's warmer down here in the SW. Passive houses often do better than 15kW/m2/year.

We've got through 2m3 of soft wood this Winter, about 3000kW or 20kW a day on average for 16-20°C. I'm still improving the insulation so each year is a bit better. We'll probably only light the stove another three or four times this heating season. The sun is currently warming the room nicely: 17.9 this morning and 19.2 now, there's fresh snow at 1000m.

wood has a consistent energy density as lignin is lignin. So Wood has a net calorific value (NCV Dry) of 18.3 MJ/Kg. Thats for "Dry" and they mean really dry. Oatmeal 17MJ/Kg, Straw 15 etc.

the calculation to determine net energy after moisture is:

NCV Dry x (1-Moisture %) - (2.443 x Moisture %)

so

18.3 x (1-5%) - (2.443 x 5%))

18.3 x 0.95 - 0.122

=17.263 MJ/Kg, which when converted to kWh by dividing by 3.6 gives

4.8kWh

but those figures say your house isn't well insulated. A passive house project in Alsace has no heating system at all

Ed, a passivhaus isnt just insulated its leak free. Mine is a converted barn. It beats all current reg targets and is relatively speaking well insulatated. Passivhaus targets are completely unreasonable for 18th Century barn conversions without throwing hideous amounts of money at it.