Storage For Wood Pellets

Hawthorn_Pl

I have decided to switch to a wood pellet burner for central heating. I am going to house the burner in my shed and have been considering options for storing the pellet. The cheapest way to buy pellet is loose from Balcas in Eniskillen at 160 euro a tonne. They however will only deliver in 3 tonne lots. For this you need about 5.5 to 6 cubic metres of space. I am considering creating my own silo for storage in the loft area of my shed by sheeting it off in. The shed is well insulated and dry. Any thoughts on this? Has anyone else thought of this or tried it out? On the face of it it seems like a good idea as this space is never used. I am trying to figure out how much storage area is in the loft which has two A Shaped gables (see attached picture) but am not sure of the maths in working it out correctly. The dimensions of the loft area are 3.96 metres long 3.048 metres wide and 1 metre high at highest part of gable.

hargo

6 cubic metres

Evergreen

Hello Hawthorn,

A couple of things to take into consideration.

1. Can the structure take the weight, possibly up to 4 tonnes weight? If you are talking about spreading it along the entire length of the shed then you should be all right. But it might be worth putting some extra load bearing beams across just in case.

2. Extraction: You have said that the highest point is 1 meter, therefore you are going to have a long store. As a result you will need a long floor auger, they can be up to 5 meters long. Is this going to limit the 6 cubic meter target? Remember you need to "V" the floor so that the pellets will fall into the auger without having to be poked with a stick. Also, the long auger comes at a cost! Including motor, gearbox and floor augers you could be upto 1400 notes before you know it.

3. Filling: If the store is too long then you need to give some thought to how far the truck will be able to blow the pellets across the top of your pellet store. Certainly you will have to keep your entry point as high as possible on the wall of the pellet store. For ease of filling you can plumb 4" sewer pipe from your pellet store to say the door of your garage where the truck can screw it's hose on.

4. Structure: I suggest that you use 24mm plywood for the side of your pellet store, it gives good strenght and will keep moisture away from the pellets. Probably a good idea to treat the outside of the ply with a water proof varnish or similar. Also, it is vital that you put a lid on the store in order to prevent condensation drops falling from the roof into the pellets - it doesn't matter if your roof does not condensate, put a lid on the store anyway.


Working out the area is a different matter: The V shape is angled at 45° on both sides so half of your loft with the most amount of area is gone straight away. Can you get 2 meters wide before the V hits the rafters? if so then you will have 1 cubic meter for every meter long the area is.......

I think you need somebody that is good with maths to work out the rest.

Ned

Hawthorn_Pl

Remember you need to "V" the floor so that the pellets will fall into the auger without having to be poked with a stick. Also, the long auger comes at a cost! Including motor, gearbox and floor augers you could be upto 1400 notes before you know it.

Thanks hargo for the maths. I presume its half the width x perpindicular height x length. That gives 6 cubic metres.

The Auger sounds very expensive. I intended to use a mini hopper that can store 300 kg of pellet i.e. 2 to three weeks supply. I would therefore use the loft area as storage and maybe manually fill the hopper every few weeks or so. I intend to leave a few access hatches to access the loft area. Balcass said you need a 4 inch coupling for them to be able to plug their pipe into it. If this is located high on one gable would it blow the pellet to the other end
(3.9 metres)
Surely kitting out a loft using proper materials and insulation will be much cheaper than investing in an expensive outdoor galvanised silo.

Hawthorn_Pl

Also, it is vital that you put a lid on the store in order to prevent condensation drops falling from the roof into the pellets - it doesn't matter if your roof does not condensate, put a lid on the store anyway.

Hello Evergreen
I intend to insulate between the rafters directly under the tiles and then sheet that as well. Is this what you mean by a lid? Should I be thinking about some form of ventilation or is this unecessary?

rooferPete

Hi Hawthorn,

I had a similar enquiry a while back and contacted Balcas mainly to see if there would be any problems filling the tank, which has been covered by Evergreen.

Their concern was the possiblity that fine dust would not be contained within the tank and if memory serves they quoted a case where the dust had followed electric wires to the fuse box or switch causing a fire.

Could be worth checking out before you build the tank, for what it's worth my opinion is if Balcas see any possibility of a consumer claiming damages because they filled a tank they would be perfectly within their rights to refuse to fill it for you.

.

Reyman

Is this storage shed attached to the house ? If it is, you could be getting into a fire risk problem. I'm not sure that your house insurance would cover it.

Hawthorn_Pl

No Reyman. The Storage shed is not attached to the house. It is stand alone about 6 metres from the house.
Thanks for the reply rooferPete. I can understand the concern about electrics and fine dust. There would be no electric cabling in the loft area. I was proposing a totally sealed and insulated area that the 3 tonne of pellet could be blown into for storage.

tinofapples

Would any of those oil tank/bottle bank manufacturers be able to provide a suitable storage tank which could be left in a garage I wonder ?

ShowAndGo

Hi Hawthorn,

I am in the same position as yourself. I have a double garage (similar design to that in the attached gif) that is going to hold my wood pellet boiler. From what research I have done it seems that real savings can only be made at the moment if you buy the pellets in bulk. So I too was hoping to use the loft area in the garage for storage.

My plan is get the boiler installed and running and start using the bagged pellets (€250/tn) and in the mean time investigate the bulk storage fully. I had a quick look at the safety instructions for the Villa hopper, http://www.gerkros.ie/gerkros%20pdf%20manuals/Gerkros%20Villa_GB.pdf, and a few things jumped out at me that would have to be addressed with any homemade hopper.
The dust/ventilation issues.
The pressure used to blow the pellets into the hopper
Ensuring that the pellets are equal dispersed in the hopper when they are dispensed so my garage roof doesn’t collapse.

I was quoted over €2000 for a 3.5 tonne hopper from one supplier. I think it was one of the Villa hoppers that Gerkros do, but I am not too sure. I was talking to another guy in the industry and a customer of his took the auger from his 300kg hopper and used it to make if own bulk storage hopper (don’t know the size). I don’t know about you but I don’t think my DIY skills will stretch that far!

Hawthorn_Pl

Hello Show and Go
Glad to see that there is someone else out there who is thinking of doing the same as me. Here is what I know so far.
My loft space is about 6 cubic metres.
0.65 of a tonne of pellet takes up 1 cubic metre therefore you need at least 4.5 cubic metres to store 3 tonne of pellet which is the least that Balcas will deliver.
Balcas are currently developing a pellet bagging plant which will become operational in about six months. This will allow customers to buy at source if they wish and save on cost. There are also rumours of new wood pellet factory setting up in Galway and Limerick in the near future.
To blow the pellet into the loft you would have to fit a 4 inch male coupling so that they could hook up from the truck.
The storage area has to be free of any dampness and condensation so that the pellet is kept dry at all times.
What I am not to sure about is what provision if any has to be made in your storage area for ventillation.
Anyone??

rooferPete

Hi,

Yes you must have a ventilation pipe to allow the air escape while the tank is being filled.

If you can sacrifice 2m x 2m floor area and most garages have 2.4 + to the roof joists why not make your tank standing up ?

Ply on the joists like a ceiling and make the walls using 4" x 2" and plywood screwed together with a couple of perspex panels to keep an eye on the fuel and you can have a tank capable of holding in excess of 9 cubic metres.

.

Evergreen

Hi Hawthorn,

Pete has a good point there, even if you reduced the size to 2 x 1.5 x 2.5high you will have about 6.1 cubic meters.

You need to plan your storage space to hold at least 3.5 tonnes, delivery can be up to 2 weeks from date of order so you need to order with about 0.5 tonnes in your store. Of course you may receive delivery the day after you order so you need to be able to pile 3 tonnes on top of what you already have.

Ventilation is essential for escaping air when your store is being built, best to try and lead a piece of pipe outside so that your shed doesn't fill with dust. Place some fine mesh over the end of the vent to prevent rodents crawling back into the pellet store - they don't burn too well in pellet boilers

There is a company in Cork that sell the nozells that the delivery truck can screw onto - they are about EUR 20.00 each

All the best,
Ned

ShowAndGo

I had a quick chat to a friend of mind last night who is an engineer. He also mentioned that ventilation was must with some kind of wire mesh prevent any rodents making a comfortable home for themselves.

When I roughly described the structure of my garage he said he wouldn’t recommend what I was trying to do. He felt that the span across the garage (about 5m with 9 inch joists) was too great to take the load from the pellets. I am going to double check my measurements and go back to him to get a definite answer, but I think I'll be going with Pete's idea and building something on the floor of my garage.

What distance have you got between your boiler and house? How do you intend to insulate the pipe that will carry the hot water from the boiler to the house? My plumber was talking about some kind of pre-insulated double pipe? I am sure it is great but the prices he was talking about sounded really expensive!

Have you had any thoughts on how you are going to dispose of the ash? From my calculations one load from Balcas will generate 150kg of ash. Can this be dumped in a compost bin?

I heard Balcas produce pellets to the European standard and not to the Austrian or German standards, I haven’t had a chance to investigated the difference between them. In any case I am thinking of going with as Gerkros boiler and they have confirmed that Balcas pellets are suitable for their boiler.

Hawthorn_Pl

Hi Evergreen. Thanks for your reply.
That is a possibility. What is the name of the company in Cork that supply the coupling fitting?
Where is best place to locate the coupling in your store? I presume it would be at the highest point?

Hawthorn_Pl

What distance have you got between your boiler and house? How do you intend to insulate the pipe that will carry the hot water from the boiler to the house? My plumber was talking about some kind of pre-insulated double pipe? I am sure it is great but the prices he was talking about sounded really expensive!

About 10m of pipe would have to be used to get from boiler in shed to house in my case. You would have to use Calpex. This is a pre insulated system that contains your flow and return.There is very little heat loss. It is expensive, about 40 euro a metre but probably a good investment as it will make your system more efficient. Why are you picking the Gerkros boiler? Is it the best that is out there in terms of efficiency and value for money?

ShowAndGo

Why are you picking the Gerkros boiler? Is it the best that is out there in terms of efficiency and value for money?

Good question, I am glad you asked! I am nearing the end of a self build at the moment and with the rush to get things finished up I have somehow got stuck on these rather investigating it properly for myself!!

From other posts I see some people have recommended the Scotte boiler. Also on the Gerkros site they don't seem to provide an efficiency rating for their wood pellet boilers???

dras

Ash - I doubt that there will be 150kg of ash per load (although that is only 5%) but even if it is you can use it in the garden to dig into the beds.

Can someone post the name of the nozzle people in cork please?

tadhgmorris

i have an idea that might seem crazy.

i have a good sized garage which currently contains my oil burner. i have an wood pellet stove in my house so i am using both oil and pellet.

my idea is (if it works) amazingly cheap to put together.

why not buy 3 largest size skippy bags. http://skippybag.ie/

these are a very strong but soft flexible rectangular container. normally used for the purpose of waste material.

i could build a wooden frame around the floor i.e. four pieces of wood to form an internal perimeter of the skippy bag. this would remain permenantly. then some uprights forming a frame giving the skippy bag some rigid strength. then some ply wood over the top to create a roof.

i now have a large contained box 6ft x 6ft x 4ft about 2 tonnes. so if i make two or three of these.

i need a 4inch hem lock i think its called that the truck locks on to in order to blow the pellet in. this would be built into the roof of the skippy bag. and the roof can be lifted off once filled and placed on the next bag awaiting filling. ventilation of dust can be done by having a circular hole cut into the roof . with a ventilation tube trailing out a door way or window or whatever .

the only problem i see is in retrieving the pellet for use. i foresee using a bucket of some sort. but what about when the skippy bag is nearing empty . i think it will be difficult to reach into it to get the pellet.

i would appreciate any suggestions or point out any errors i have made in my plan. thanks