wood gasification boiler

hammer73

Do any of you have experience with wood gasification boilers. I have planning in for a 2500 square foot house and plan to put in a gasification boiler but am unsure of the consumption of wood it will have. How many cubic metres of wood will it typically burn through in a year. I appreciate that it will depends if the house is occupied all day or not, if you have experiences please outline consumption as well as how often it is on.

Thanks for any help

dontom

I heat 5500 sqft with a 65 Kw gasifier and I use approx. 35 qbm per year
and have 5 winters behind me.

viztopia

dontom, what make do you have and would you recommend it?

reilig

I have a 25kw atmos gasification boiler with a 1500 litre buffer tank that will be ready to be lit by next weekend. I'm hopeful that it won't be too hard on fuel. Both of us are out of the house working during the day, so its likely that 1 burn per day will heat the house (2000square meters) and the hot water (300 litre cylinder.)

So I might be able to give you some feedback after next weekend.

There's a thread on boards.ie under renewable energy on gasification boilers if you want to do a google on it.

dontom

Viztopia,

yes I'm happy, it's HERLT boiler, not the cheapest but it works perfect.

winterbourne

2500ft2 is approximately 250m2
This would be the top end of an efficient 25kW Gasification boiler on a well insulated property and would use about 6 tonnes of seasoned wood a year for all CH + DHW requirements. This is approximately 9m3 of hardwood and would resembe about 3/4 wheel barrow a day.

reilig

winterbourne wrote: »

2500ft2 is approximately 250m2
This would be the top end of an efficient 25kW Gasification boiler on a well insulated property and would use about 6 tonnes of seasoned wood a year for all CH + DHW requirements. This is approximately 9m3 of hardwood and would resembe about 3/4 wheel barrow a day.

After using my boiler for a year now, 9m3 might be a bit of an underestimation. I'd recon about 12m3 would be a better guess (far more if you are using softwood). My boiler holds almost a wheelbarrow full in one fill. In the 4 weeks of snow that we had last christmas, I was burning between 2 and 3 barrows per day because the heat was constantly on. I had underestimated the amount of timber that I needed around this time and often supplimented a fill with turf which I found burned far better than softwood (it burned for much longer) and almost as good as hardwood. These 4 weeks of snow saw me use almost half of my supply of wood, and i estimated that I had at least 3 months more that I would need to light the boiler on a daily basis.

Thankfully, I had only to light my boiler once per week since the beginning of may up to now - this was for DHW heating.
For anyone thinking about installing one, they're great, if you're used to lighting a fire every day. Wood burning is a lifestyle. If you're not prepared to light it every day, then go for oil or pellets.

Also, wood is going to be very expensive this winter. Thankfully I have my own supply which should last another few years - maybe i'll have more planted by then.
But if you don't have your own supply and have to buy processed wood from a supplier to fuel it, then it may not be worth your while either and you should look at an alternative fuel.

Caoimhín

Get on to your local forester lads, he can sell you 40 tonne of small diameter (pulp wood) for about €1000.

PM me and let me know where you are and I can give you a contact number.

endacoffey

Caoimhín wrote: »

Get on to your local forester lads, he can sell you 40 tonne of small diameter (pulp wood) for about €1000.

PM me and let me know where you are and I can give you a contact number.

Hi there Caoimhin,
Can you please post details of a bulk wood supplier in the Longford / Westmeath area. I have been looking into the Wood asification option and just need to do sums on sulpplies, outlay, etc,
Thanks, Enda

Caoimhín

Enda,

I have a few contacts for Coillte foresters who might supply you with pulp wood. Pulp wood is usually Sitka Spruce so you might want to check is it is compatible with your boiler. The boilers I have glanced at often only take broadleaf/hardwood so I dont know if Sitka would be suitable. Sitka can be made up of 50 - 60% water so it might not burn the best when it is green (recently cut).
I have a bit of a plan myself to dry out Sitka in a shed for 18 months which would get it down to maybe 14% moisture levels but this requires a lot of storage space.

There arent really any suppliers of bulk hardwood/broadleafs. The reason for this is because most broadleaf planting only started around 10 - 12 years ago. Often the value of cut broadleaf timber is so low that it isnt cost effective to cut it and draw it out of the forest.
If you do need broadleaf it might be worth your while looking through the papers for someone selling it by the trailer/bag and making a deal with him.

The number for the local Coillte offices in Mullingar is 044 9342770

reilig

To buy lorry loads of firewood, you need to contact the harvesting managers. Your local Coillte office won't really have a clue where to send you (well mine didn't anyway.

here's a list harvesting managers nationwide with their contact details:

http://www.coillte.ie/fileadmin/user_upload/pdfs/Log_Sales/Harvesting_Managers_3.pdf

endacoffey

Hi Caoimhin,
Thanks for your reply, can you please clarify if wood pulp is actually "Mushed up " wood or is this a generic word for smaller wood pieces. I'd imagine at this stage that if I go for a wood gasification unit, I'll probably be looking at larger tree trunks (greater that 100mm diameter) and process it myself. I will probably cut and store outside and place into a smaller shed 6 months before burning. I really wouldn't have storage for a large amount of "Mushed" wood.
Again, I'll have to look at the suitability of Sitka with Wood Gasification units, but at this stage I'll have to consider everything.
Thanks again,
Enda
P.S. Thanks to all other respondents

Caoimhín

endacoffey wrote: »

Hi Caoimhin,
Thanks for your reply, can you please clarify if wood pulp is actually "Mushed up " wood or is this a generic word for smaller wood pieces. I'd imagine at this stage that if I go for a wood gasification unit, I'll probably be looking at larger tree trunks (greater that 100mm diameter) and process it myself. I will probably cut and store outside and place into a smaller shed 6 months before burning. I really wouldn't have storage for a large amount of "Mushed" wood.
Again, I'll have to look at the suitability of Sitka with Wood Gasification units, but at this stage I'll have to consider everything.
Thanks again,
Enda
P.S. Thanks to all other respondents

Sorry Enda, "pulp wood" is the generic term for small diameter wood that is taken out of the forest in its first "thinning". It is called pulp because it usually goes to the sawmills to be pulped for paper and chip board.

Here is a good link to get an idea of the size and price of timber that Coillte sells. http://www.coillte.ie/coillteforest/log_sales/quarterly_standing_contracted_prices/
It might be better to go through the local forester than buying through the auctions.

endacoffey

Hi Reilig,
I've been looking into the Wood Gasification option for quite some time now and am pretty sure that I am going ahead with the Atmos 25 kw boiler. My house size is similar to yours (2100 sq.ft) and is reasonably well insulated - 50mm insulated plasterboard, 200 mm of attic insulation which I will probably "Up" soon aswell. I spoke to the sales man in M Large who told me tha I could get a 32kw boiler for little extra but this would mean increasing the size of the buffer tank to 2000 litres. I am wondering is this "Overkill" altogether and ultimately a waste of fuel. He also advised buying a tank with a coil. I was wondering is this really necessary as I have a water cylinder in the hotpress.
Are you still happy with the system overall? - particularly as last December was so cold.
I also looked at the Gamlet tanks. Was your tank delivered with external high density insulation? The cross section drawing seems to suggest it does but the picture of a black tank on the Kotly website seems to suggest otherwise (can see the weld line on top in the photo)
Thanks again for your help,
Enda

reilig

I'm very happy with the system. My only probem was a frozen circulation pump - but that was my own fault. Plenty of heat and all free because I have access to free wood. My system runs through the hot water cylinder in my hotpress so no need for a coil in the buffer tank. My tank was delivered with high density insulation. Its fine. Loses less than 5 degrees per day.

Bigger boiler means less lighting it. If I ever have to replace my boiler I will put in a 32kw one but use the same 1500l tank. 1500l would be quite sufficient for a 32kw IMO.

Hope that info helps.

endacoffey wrote: »

Hi Reilig,
I've been looking into the Wood Gasification option for quite some time now and am pretty sure that I am going ahead with the Atmos 25 kw boiler. My house size is similar to yours (2100 sq.ft) and is reasonably well insulated - 50mm insulated plasterboard, 200 mm of attic insulation which I will probably "Up" soon aswell. I spoke to the sales man in M Large who told me tha I could get a 32kw boiler for little extra but this would mean increasing the size of the buffer tank to 2000 litres. I am wondering is this "Overkill" altogether and ultimately a waste of fuel. He also advised buying a tank with a coil. I was wondering is this really necessary as I have a water cylinder in the hotpress.
Are you still happy with the system overall? - particularly as last December was so cold.
I also looked at the Gamlet tanks. Was your tank delivered with external high density insulation? The cross section drawing seems to suggest it does but the picture of a black tank on the Kotly website seems to suggest otherwise (can see the weld line on top in the photo)
Thanks again for your help,
Enda

stanflt

im heating the house 3200ft with a stanley stove linked directly to the 800lt expansion 3coil tank. ive 8m2 of solar panel and oil as back up. the house is only in its 2winter. when i switch on the rads it takes the hot water from the 800lt tank not the oil. i am being honest i still havent set up the oil tank-im burning an awful lot of timber but i think i is worth it. if i did have the oil set up it would only turn on when water in cylinder is less than 55. this year ive burned roughly 3 mature trees. chainsaw needed a new bar! i am quiet happy cause the tractor diesel took 1800 last week and didnt need any house oil:) enough bills with out that

moy83

stanflt wrote: »

im heating the house 3200ft with a stanley stove linked directly to the 800lt expansion 3coil tank. ive 8m2 of solar panel and oil as back up. the house is only in its 2winter. when i switch on the rads it takes the hot water from the 800lt tank not the oil. i am being honest i still havent set up the oil tank-im burning an awful lot of timber but i think i is worth it. if i did have the oil set up it would only turn on when water in cylinder is less than 55. this year ive burned roughly 3 mature trees. chainsaw needed a new bar! i am quiet happy cause the tractor diesel took 1800 last week and didnt need any house oil:) enough bills with out that

you wont beat the stanley superstar i have the exact same in my house ive burned alot more than three trees id say though

endacoffey

Hi Reilig,
Thanks again for the info.
I am pricing options at the moment and Kotlys shipping costs seem to be prohibitive. Did you use their shipping company. I priced all in - Boiler, 2000 l buffer tank, etc and the shipping came in at 800 euro.
Have you any suggestions on getting around this? Perhaps you could PM details of your contact in Kotlys. Also, would you have ordered anything else from Kotly that you ended up getting here?
Regards,
Enda

reilig wrote: »

I'm very happy with the system. My only probem was a frozen circulation pump - but that was my own fault. Plenty of heat and all free because I have access to free wood. My system runs through the hot water cylinder in my hotpress so no need for a coil in the buffer tank. My tank was delivered with high density insulation. Its fine. Loses less than 5 degrees per day.

Bigger boiler means less lighting it. If I ever have to replace my boiler I will put in a 32kw one but use the same 1500l tank. 1500l would be quite sufficient for a 32kw IMO.

Hope that info helps.

Doctor_L

I know this may seem a bit mad but I am considering a thermal store of 4000 litres with a 50kw boiler. A colleague of mine has 35kw with a 5000 litre tank which means he only has to fire it up every 2 - 3 days he usually fires it up and reloads after 4 hrs.

The heat demand for my house is 20kw approx so I calculate that I can get 2 days heating for a 2000 sq ft house with 18 rads. The price difference between 25, 32 and 50 is not huge and the 50kw takes a bigger log of 730mm when compared to the 25 and 32 which takes a 530mm log.

The big outlay is going to be the tank and it will be a monster at 180cm by 232 cm. But a large thermal store seems to make sense.

Can anyone recommend tank suppliers with decent prices?

Agri contractor

Has anyone tried to produce electricity from wood gasification boilers. Producing 20kw of heat should produce 6kw of elecricity looking at doing something like this. I have being in contact with a woodgas enthuasist in finland. He can supply drawings.

Also has anyone done this ? Speaking to a farmer last week, he is shreading paper soaking it in water for a day then compacthing it into small blocks and leaving to to dry, when dried he put it into his wood gas boiler. He is delighted with the heat.

reilig

Agri contractor wrote: »

Has anyone tried to produce electricity from wood gasification boilers. Producing 20kw of heat should produce 6kw of elecricity looking at doing something like this. I have being in contact with a woodgas enthuasist in finland. He can supply drawings.

Also has anyone done this ? Speaking to a farmer last week, he is shreading paper soaking it in water for a day then compacthing it into small blocks and leaving to to dry, when dried he put it into his wood gas boiler. He is delighted with the heat.

I spoke to a guy in a company in monaghan who was looking at stirling engines to produce elecrtriciy off gasifying boilers but to date he has not been able to make it viable.. First off, stirling engines are so expensive, secondly they are dangerous with high pressure lines etc when you go looking at models of up to 6kw.

20kw of heat to produce 6kw of electricity is not a great conversion figure in comparison to electricity being generated direct from biofuels, peat, coal or oil. I can't see it happening in the near future.

reilig

endacoffey wrote: »

Hi Reilig,
Thanks again for the info.
I am pricing options at the moment and Kotlys shipping costs seem to be prohibitive. Did you use their shipping company. I priced all in - Boiler, 2000 l buffer tank, etc and the shipping came in at 800 euro.
Have you any suggestions on getting around this? Perhaps you could PM details of your contact in Kotlys. Also, would you have ordered anything else from Kotly that you ended up getting here?
Regards,
Enda

Shipping was about €500 for me for the whole lot - but I didn';t get my boiler from them. I dealt with Thomas there. He is in charge of sales and shipping to English speaking countries. Just call the number on the website.

djmc

If anyone is intrested I have a baxi multiheat boiler with 5 years
I have burned wood pellets wood chips barley wheat and find it very good
If anyone has space in there garage there is some good value ones on done deal at the moment I paid eight thousand for mine and am happy
Makes me wonder why people are selling them so cheap maybe they just want oil or dont like cleaning out ash or something:rolleyes:

reilig

djmc wrote: »

If anyone is intrested I have a baxi multiheat boiler with 5 years
I have burned wood pellets wood chips barley wheat and find it very good
If anyone has space in there garage there is some good value ones on done deal at the moment I paid eight thousand for mine and am happy
Makes me wonder why people are selling them so cheap maybe they just want oil or dont like cleaning out ash or something:rolleyes:

Some of the baxi boilers gave a lot of trouble. There are threads all over the internet about augers getting clogged and just causing general hardship for people who did not know what they were getting themselves into by buyng a pellet boiler. That said, I believe that most of the problems were caused by poor quality pellets which would not feed into the boiler properly. Also, some people didn't invest properly into storage facilities for the pellets and this caused problems with the pellet quality (dampness etc.). As I said, there are threads all over the internet from Ireland an the uk from people who took them out and replaced them with oil boilers because they found them too difficult to use and unreliable - mostly through faults of their own.

djmc

I would say they need to be cleaned every few weeks and ash taken out every day or two but I have burned fair rubbish in mine and once it was dry I never had a problem but anything that burns solid fuel needs more work than oil or gas.
The settings on the control panel also take a bit of getting used to if they are set wrong it wont work right or will burn too much costing extra money

reilig

djmc wrote: »

I would say they need to be cleaned every few weeks and ash taken out every day or two but I have burned fair rubbish in mine and once it was dry I never had a problem but anything that burns solid fuel needs more work than oil or gas.
The settings on the control panel also take a bit of getting used to if they are set wrong it wont work right or will burn too much costing extra money

I totally agree. Burning any type of solid fuel is a lifestyle. You have to prepared to clean regularly.

tap28

Hi,

I'm thinking to going down the gas boiler route and have a few questins. Hope ye can help.

My home is a modern well insulated 2400ft2 house.

One section of my shed can store 24m3 of wood easily.

Would this amount of timber be enough to heat my house for the year?

I'm in the middle of planting 500 alder and eucalyptus trees is this over kill?

I know this is a how long is a peace of string question but how many trees would I need to plant to have 24m3?

Thanks

Tap

Caoimhín

tap28 wrote: »

I'm in the middle of planting 500 alder and eucalyptus trees is this over kill?

I know this is a how long is a peace of string question but how many trees would I need to plant to have 24m3?

Ok, ive been looking into this in the pat few years, i did a module on it in university too. At the moment there are few trials or research at the moment (maybe a post grad could use this as a research project?).

Anecdotally, there have been some trials in Holland and practical endeavours in Scandinavia. The results have shown (again, these are not verified) that 6 acres of mixed broadleaf species, managed in a continuous cover coppice system is enough to heat a 2000 sq foot house. That includes all heat and warm water.
I understand that this system used a combination of log gasifiers and wood burning stoves.

Its hard to say if 500 trees are overkill since you haven't said what area you are planting. Generally, planting the trees at 2m X 1.5 Metres will give you a stocking level of 3300 trees per hectare (a hectare being 2.471 acres).
Planting at this density will give optimum use of nutrients in the soil as well as promoting upward growth.

I wouldn't be crazy about eucalyptus. It is very susceptible to frost damage and while it has a high calorific content for burning, it doesn't coppice very readily. It depends on the soil you have, the elevation, what part of the country you are in but generally a 30;30;30 ratio mix of alder, hazel and/or Oak and Birch. The hazel and Oak should be planted in the drier areas while the alder and birch need a wee bit of damp.

Look, i could go on and on but if you call the local Teagasc forester he will take a walk of the land for you.

PM me if you have any more questions.

Caoimhin.

tap28

Thanks for the information.

I had decided to plant the 500 trees at 2m x 2m.

I'm new to this but if I reading your information right, I not I apologise:
2000ft2 = 6 acres
2400ft2 = 7.2 acres
2.471 acres = 3300 trees
7.2 acres = 9616 trees

Based on your calculations. I would need 9616 trees to be coppiced?
If on a 10 year cycle storage needs for 961 trees.
If on a 20 year cycle storage needs for 480 trees.

I really hope my reading is wrong as my little coppice would only be a drop in the ocean.

Thanks,

Tap

reilig

tap28 wrote: »

Thanks for the information.

I had decided to plant the 500 trees at 2m x 2m.

I'm new to this but if I reading your information right, I not I apologise:
2000ft2 = 6 acres
2400ft2 = 7.2 acres
2.471 acres = 3300 trees
7.2 acres = 9616 trees

Based on your calculations. I would need 9616 trees to be coppiced?
If on a 10 year cycle storage needs for 961 trees.
If on a 20 year cycle storage needs for 480 trees.

I really hope my reading is wrong as my little coppice would only be a drop in the ocean.

Thanks,

Tap

Hey Tap,

I got your PM but it might be useful to put this where everyone else can see it.

The amount of wood that you burn will depend on the type of wood that you are burning (Hardwood or softwood). It will also depend on the size of your house and the level of insulation that you have in your house and whether you are in the house all day or you do a 9 - 5 job.

Gasifying boiler manufacturers calculate that you will burn somewhere in the region of 20 to 25 m3 of softwood per year with a 25kw boiler. In the last year I recon i have burned about 16 - 18m3. But a lot of it was willow.

I'm no heating expert but it is possible to calculate your heating needs and calculate how much wood you will need to meet these needs. Maybe someone on here can do it??

If you're going planting wood for coppicing, can I recommend willow. It has a lot of things going for it:

- It will grow from cuttings
- you can start to coppice it at year 8
- it is suitable for our climate
- it has a fairly good btu
- it loves the wet climate
- it will grow well in poor soils and absolutely loves bogland
- it dries very well, its easy sawed
- its really well suited to coppacing
- you can grow it for free by just taking cuttings off a willow and using a bit of rooting powder

While it doesn't burn as well as ash, oak or beech, it burns better than any softwood that I have tried. I recon that an acre of ground (in 8 years time) could keep my house heated for life. I've started to plant cuttings on some cut-away bog. In the mean time, I have access to hedgerows with loads of willow that needs coppacing for the next couple of years.