Heating a Farmhouse with a Wood Chip Boiler Biomass Heater - Taking you through from hedge to hearth.

This is a very interesting alternative energy project in that although it is used to heat an individual dwelling, in this case a farmhouse, it actually lies at the heart of what future energy conversion may be all about. There is a growing sense that energy and food production needs to be based around small communities.

Turning back the Clock

A few kilometres away from us is an organic dairy farm with a fine head of rare breed Normandy cows and from where we get our raw milk, cream, cider, honey, chicken grain and straw. The layout of the farm is the same as one sees in most parts of France, the buildings constructed mainly from locally sourced stone and clay, the extraction of the stone at the time of construction resulting in the formation of a large duck pond. On one side of the pool is the bread oven, still used to this day.The farm, as with our own house, has due to its its construction, a high thermal mass which makes the building warm in Winter and cool in Summer. Traditionally these farms had large open fireplaces upon which huge logs would be placed both for cooking and heating. These fires were fed from timber grown on the farm, and were highly inefficient at around 15%. 

Going backwards to go forwards

The fields surrounding the farm are divided with hedges of deciduous wood. The hedges are trimmed every 15 years and the wood is used for fuel. This cycle has been going on for centuries, maintaining the hedgerows being an essential part of the farm calendar. Traditionally, the bigger branches were cut or split into logs for the fire and the thinner twigs would be collected, tied into bundles (faggots) which could be used in the bread oven. Over the last 80 years or so this latter use has become almost obsolete resulting in most farmers/landowners burning these smaller twigs in the fields where they were cut. This amounts to about one third of the total amount of combustible material being wasted.

The solution Michael and Lydie have adopted is to heat their large farm house using a wood chip boiler, the chips are produced from ALL of the hedge trimmings.

In this part of Normandie, there are hedges of a specific type known as bocages. This is an ancient hedging system, whereby the trees were planted on the top of lines of mounded up earth, lined with local stone. Thus, creating raised hedges and obviating the need for livestock fencing. Many of these, sadly have been grubbed out and flattened over the years but others have been preserved. Not only that but some farmers and homesteaders/smallholders are either replanting them or even reinstating the ones that have been destroyed. They are a haven for wild flowers and wildlife and I'm proud to say that we have one which runs along the whole side of our garden.  If you have ever visited Cornwall or Devon, you will have seen similar beautiful hedge types.

Starting at source

On an appointed day a tractor and chipping unit arrive at the land where the wood to be shredded lies beside the trimmed hedge. On the day when we were there, the cut branches from 200m of hedge were converted into chips in one hour and 5 minutes, producing three large trailers full of fuel, sufficient for 18 months of heating of the farmhouse.

Here is a short clip of the chipper in action from our own files. The complete video of the whole system from hedge to hearth, embedded from our Youtube site will be shown at the end of this article.

The chipping machine, and grab are powered via a power take off (pto) from the transporting tractor. The tractor has to be at least 250 HP to supply sufficient power to chip the larger diameter branches. The machine is owned by farmers in the county who contributed to its purchase. Each farmer pays for the running costs incurred to process his wood. Many farmers are also now collectively producing their own biofuel and the tractor can be run on this.

The three fully laden trailers are taken back to the farm and the contents are piled in a hanger to dry. Michael told us it is possible to let the branches dry in the field prior to chipping, producing fuel that may be used immediately. The big disadvantage to this is that the cutters in the machine wear much more rapidly than when chipping 'greener' wood. So, if you have the space, let the easier-to-process chips dry in an open-sided shelter.

After a few days in the shelter, the chip mound starts to naturally heat up, this heat drives the moisture out of the chips such that after 6 months they may be transported up to the rear of the farmhouse where there is a sheltered area next to the 'boiler room'. This means that the recently vacated shelter can then be used to store straw from the summer grain harvest.

The mound can attain temperatures as high as 80º C and theoretically one could extract this heat via a heat exchanger network to supplement the energy needs. The downside to this is that the drying mound would need to be near to the point where the heat is required, the size of the mound would mean another shelter near to the house. Plus any heat exchanger would be susceptible to damage from the machines needed to transfer the dried chips to their final destination. Additionally, there would be a problem of odour. The vapour that is emitted from the pile has a strong fragrance of alcohol.

Goodbye Mr. Chips

Now we come to the final destination of the wood chips, the boiler. 

The dried chips are transferred to a loading bay in this case it is a corrugated iron sheeting silo of 4m³ capacity. Sited in the base of this is a trough in which a screw or auger operates to feed the chips into the boiler. Two spring arms rotate at intervals to sweep chips into the trough. the arms ensure that no voids can form above the trough. The screw feed and the sweeping arms' operation are controlled by the boiler. 

When we were observing it they were actuated for 5 seconds every 30 seconds. The silo holds enough chips for about 3 weeks in the winter months.

The boiler functions automatically, feeding fuel and adjusting the amount of  air needed for optimum combustion. The grate is emptied of ash which is then transferred to the ash box at regular intervals. There is a heat exchanger sited after the combustion chamber the exterior surfaces of which are also automatically cleaned to ensure optimum heat transfer.

The water heated in the exchanger passes into the coils of a 800l hot water tank. This tank provides the domestic hot water and the supply of heating water to the 15 radiators in the house. Thus the boiler is not running all the time and is re-ignited when the hot water tank temperature drops to a pre-determined point. An electrical resistance in the combustion area is used to ignite the wood.

Depending on the quality and type of wood chip being burned the ash box needs to be emptied at best every 3 weeks i.e. every 4m³ of wood chips, inferior wood such as willow will produce more ash that will require the emptying of the box every 10 days.

Pros and Cons

Pros

Using all of the trimmings from the hedges means that there is nearly 50% more fuel for heating and less pollution arising from burning the residue in the fields.

Locally sourced wood means very low fuel miles contributing to environmental impact of system.

Claimed efficiency of over 90% and low emissions means the boiler compares well with gas boilers.

Smokeless.

Ideal for small communities or a group of homesteads seeking a renewable source of heating.

Machines could be powered by Biodiesel to lessen environmental impact further.

Excellent for co-operatives (shared use of chipping equipment).

Cons

Expensive for small independent user if own production of chips desired.

Outbuilding required for bulk storage of chips.  

Cannot function without electricity.

Initial cost of the system - 25,000 Euros, in some countries there is a subsidy for renewable energy start-up but the cost is still steep, in particular if you are also needing to hire the shredder and/or buy in wood for chipping or the chips themselves.

With the ever increasing price and rapid diminishing of resources, any form of heating which can process a renewable, sustainable fuel is worth serious consideration, especially in rural areas.

Our thanks go to Michael and Lydie for the time taken in showing their system to us and to Mother Nature for providing the wood.

Now, if you'd like to, sit back and watch the film:

Thanks for dropping by and please feel free to share this article, comment and/or ask questions and if you'd like to be assured of getting the next post, then sign up to follow this blog.

All the best, Andy

© Andy Colley 2014

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How to compost urine using a straw bale. Dry toilets for all climates.

The Piddleposter

 

A great way to process dry toilet liquid for around 6 euros or 5 dollars worth of materials. 

Whether you're a homesteader/smallholder looking to cut your water consumption or someone who just wants not to have to take off muddy boots when needing to use the bathroom.....

 
...even though the cows may have something to say about you pinching their bedding.

Introduction

 

A few months ago I received a question regarding the practicality of using a dry toilet in a really cold climate.

My thoughts on this are as follows:

The solid waste from our two-bucket dry toilet system would still go into the composter, I would advise the use of larger amounts of straw to act as an insulator as well as furnishing the carbon necessary for the bacteria to work. Even if the temperatures are very low, as soon as Spring temperatures arrive, the composting process would speed up and I would expect after the passage of two years for the compost bin contents to be completely transformed. I would have said that if one already has a climate able to compost vegetable matter/ garden waste then there will be no problem with that of the toilet contents. 
 

 

The liquid waste would probably be harder to dispose. Ordinarily, our urine is diluted with grey water from the house and then poured around the garden. When the temperatures are below zero I do see a problem with the frozen ground being unable to absorb this. Fortunately for us the cold spells do not last too long and normally the soil in the more protected areas of the garden are still porous.

I realise that for people living with longer, colder Winters the liquid waste would become a burden. So, my idea is to make a composter specifically for handling “neat” urine and capable of producing a valuable compost at the end of its processing.

The straw bale composter

Human urine is 95% water the rest is a rich mixture of chemicals the largest proportion being nitrogen. To make good garden compost you need a Carbon to Nitrogen ratio of about 30:1 and so the almost total carbon content of straw makes it an ideal companion in the compost bin.

This is an idea becoming more commonly seen at outside public events as no drainage for the liquid is required. The toilet can comprise of an enclosure with a seat if needed and an appropriately placed straw bale to receive the liquid direct from source.

French designers Faltazi have come up with an easily attached folded polypropylene or stainless steel 'funnel' so as to produce an ecological pissoire. The funnels are pushed into the sides of a straw bale at the appropriate height for men. http://uritonnoir.faltazi.com/en/

My experiment was to make a suitable container for a straw bale and empty the liquid waste from its receptacle onto it every day and see what happens to the urine and the straw.

The Design.

Obviously the compost bin has to fit around a straw bale. The standard bales in Europe are now huge cylinders and are designed to be mechanically lifted and dispersed throughout the farmer's barns. 

The organic farm where we buy our grain for our birds has these same sized home-grown organic straw bales and he uses one each morning and night for the bedding of his 50 head Normandy herd. 

Even so he has other livestock areas where he only uses part-bales. If we give the farmer 24 hours notice he can take a part-bale and re-roll it to a more manageable size. This is so it will fit into the rear of our estate car/station wagon, even then it is still quite a push to manhandle it into place. For 5 euros or 6 dollars we got this bale with enough left over in the deal to keep the Hen Houses supplied for several months. So for a small initial sum you can end up with some great and truly organic compost! You will probably have an organic farmers' register for your area, so check out the dairy or other livestock farms and see what they have on offer. Mixed arable farms will also have straw and again I would always go for a certified organic farm, where you can be assured of them not using chemical sprays and/or synthetic fertilisers.

These bales when laid on their sides in fields will shed rainwater for some considerable time, a desirable feature for the farmer but not for the urine composter hence, the bale has to stand on its end to expose the more porous part of the bale uppermost when in the composter.

 










The link for the design and construction of the compost bin on the left can be found here:
Pallet wood compost bin 


If you've seen my other compost bin design you will know of my sliding wall plank system that I developed to ensure easy access for emptying and the facility to exchange rotten planks with new ones. For the new bin I opted for only the front elevation to be of the sliding plank format, the other three walls were to be pre-made in the workshop. This would still mean that the wall panels would be easy enough to carry into the garden for assembly on site.

The cylindrical straw bale has a height of 120cm. Perfect for my needs as the standard pallet plank is exactly this length.

A waterproof lid fits on top of the container to ensure weather protection.

Fabrication

The three pre-constructed walls were made by nailing pallet planks to top and bottom horizontal rails. The wooden rails of each wall were longer than the wall width. This protruding portion fitted over or under the other walls' rail, a clearance hole was drilled through the two rails and a threaded bar was inserted. Nuts on the threaded bar were tightened once the walls were in position. 
 

On the front elevation of each side wall was a vertical post running from top to bottom to which the spacer rails were screwed and onto these were screwed the retaining rails. The resultant gap between the post and the retaining rail had to be enough to allow the wall planks to pass.

One important point is that the upper rails of the side walls projected beyond the rear wall of the composter, this to provide the pivot point for the lid.

Here is the step-by-step film showing the construction:

All the best and thanks for dropping by. Feel free to comment ask for information and/or share this article.

Cheers, Andy

© Andy Colley 2014

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DIY Pallet Wood Hen House Chicken Coop Part 4 - Assembly contnued and Finishings

Natural Finish - A piece of buddleia branch trimmed to make way for the Hen House is used to fashion its doorknob.

It's day three of the Assembly of the new Hen House. The chicks have spent their first night in their new home. It's bigger and roomier than their old one, never again will I design or make a hen house which doesn't have space for us to stand upright! I also found that putting a door in both back and front makes for ease of cleaning and is a good way of removing perches and keeping the house aired in hot weather. The house is sited on the far side of the garden and is in the angle of the back wall of a neighbouring longère and the North bocage (raised hedge). In the Winter it receives the sun quite early in the morning, when the rest of the garden is in the shadow of the house, which runs the entire length of the garden, some 50 metres (164 feet). It's  a regular suntrap in the Summer, which is why the fig tree does so well there and the hens, sybarites through and through, love it.

 

Breakfast in front of the New Hen House.  

Raising the Roof

We start the day by putting the gable ends in place. These are temporarily held in position with diagonal supports to the walls, which will be removed once the ridge purlin is in place.

 

Using a straight edge ensures that the wall and gable end are in line so that the ridge purlin brace may be fitted.

The House is now beginning to take shape with both the gable ends in place. We are now ready to fit the ridge purlin.   

The ridge purlin is measured and cut to length once the gable ends are in place.  

The ridge purlin is screwed to the inside face of the gable end apex. Screw holes are drilled through the gable end frame prior to fitting the purlin in place.

Once the purlin is in place, the braces can be fitted to each end of the Hen House. These braces are designed to take the roof load off the screws securing the purlin to the gable end. The roof load is thus borne by the side walls and floor. 

Once the ridge purlin and brace have been screwed together, the temporary diagonal supports may be removed.

 

Furring strips are now fitted to the ridge purlin. 

The roof is now ready for the panels to be fitted.

The panels are screwed to the walls and gable ends from the inside and from the outside to attach the ridge purlin.

  

The most expensive part of the Hen House, a good quality tarpaulin, can now  be fitted.

The surplus material is trimmed off and battens cut from pallet wood are used to fix the tarpaulin to the underside of the roof panels.

The open sides of the pallet base are sealed with planking, nailed to the wooden blocks.

The decoration with découpage is made from paper napkins.

The building inspector calls to assess the job. He's a white-laced buff crested and bearded Polish, one of three brothers who are joint heads of this house.







If you want to see our Polish chickens in action:

There is another post here, which shows how I used butt joints to construct the roof panels of pallet wood too. This makes the house even cheaper for those of you who don't have left-over or recuperated tongue & groove cladding.

Thanks for dropping by and please feel free to share this article, comment, ask questions and if you'd like to be assured of getting the next post, then sign up to follow this blog.

All the best, Andy

© Andy Colley 2014

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DIY Pallet Wood Hen House Chicken Coop Part 3 - Assembly.

The little touches that count and just give the Hen House a feel of home.

It's day two and the Chicks have still to try out their new home. Now the foundations are down I'm hoping all will go well. The big question you may be asking is how do I know all my workshop fabricated kit will fit together? Quite simply because whilst it was pouring down with rain outside and there was no chance of erecting it, I did this....

Set the whole thing up in the Kitchen! It's something I did before, though not indoors, when I made the roof structure for the Tiny House in the Garden. It's a really good idea if you can just do a trial run fitting a project together somewhere you can easily get all round access  rather than waiting until the project is in situ.

It also means I can check the alignment of bolt holes in the corners and mark them up for ease of assembly. After all, who knows how long the dry spell of weather will last.

The pallets are laid onto the prepared foundation blocks. Providing they are standard pallets, all four should be at the same height.

The rear wall and one section of the side wall are assembled to make a self-supporting structure, to which the other walls may be attached.

Andy's Handy Handling Hint

 

To get the roof panels up through the forest garden without causing damage to trees and bushes and for ease of manoeuvre. I made this simple pallet wood bogey. I used wheels recuperated from an old lawn mower.

It also means that the project can be handled by a person working on their own.

As the night comes down, two roof sections form a temporary cover, secure enough to allow the hens to spend their first night in their new home.






The time was ripe to build this new house because this year Sue has launched us into Cochin Pekins (twelve new babies in all) and seven of them have just been left by their Mother so they are ready to enter a group. As chicks with a mother hen, they have had the right to pass throughout the garden but left alone they need to be attached to a house so as to establish territorial rights. A brand new house, which is new for the whole group makes it much easier for the established flock to accept the chicks because territorial possessions such as the house and perches have changed. If you want to see the new chicks in action:

The next part of the assembly is quite involved so needs a post to itself to complete and it can be found here

Thanks for dropping by and please feel free to share this article, comment, ask questions and if you'd like to be assured of getting the next post, then sign up to follow this blog.

All the best, Andy

© Andy Colley 2014

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Setting up a Dry Toilet - Stop flushing the Planet's Precious Resources and Your Money down the Sewers. Introduction

Preamble: A Few Facts and Figures 

(in French but bills are bills in any language!)

Before

&

After

 and in financial terms too.....

What is interesting about the above bill is that the actual water used has gone from 45 cubic metres to 13 cubic metres, so the water consumed now costs us over two thirds less than before. The main cost is the standing charge, which is now equivalent to nearly double the price of the water we consume! Even more of a reason, in our new place, to get a borehole dug. A good gauge to tell you when you should be off the grid and consequently off mains water, is when your consumption costs are less than the standing charges or line rental.

Three Great Reasons to Sort out Your Own Manure

Two years ago due to a change in car-parking, we ended up entering our usual visit to the Salon Ille et Bio - Guichen Organic Fair, via the front entrance, Community Hall rather than our usual way through the Community Organic Garden. For the first time we noticed a whiteboard, where visitors could express themselves with some sort of observation or thought for the day. The visitor in front of us took up the marker pen and wrote "Flush toilets are an abomination - they should be banned". Travelling home, an hour's drive, gave us plenty of time to think over and discuss this amongst other great things we had seen at the Fair.

Time was in the essence because an EEC Directive meant that our village was now to be put on mains sewage. The result would mean that like it or not in the following years instead of grey water eventually filtering back into the land, which was fine by us, we use no chemical products whatsoever, all our water would end up in the Sewage Treatment Plant. For the past few years we had had a waterfilled recycled wine bag in the cistern to cut down the volume of water at each flush this but this now seemed insignificant. The water, the urine and the solid mater, were all a useful by-product of us eating and drinking organic food, we decided the time was ripe for us to take control of our own valuable resource. We needed to break away from an insane system, which pours chemicals and energy into water to get it to potable standard only to flush it down the sewers. If we needed a further incentive, then saving money completed the deal. When we got back home we started to draw up plans.

 

My system costs under 10Euros/Dollars, I started with the compost bin, which can also of course be used as the model for a standard compost bin for your garden and household waste. The recommended time for the humanure to be  ready for use is two years but already after three months you will find it has started to rot down. The bin is made of untreated, recycled pallet wood and the only other item you will need to make this work is the sawdust. Trust me it does not smell!. In the following articles I will show you how I set up our dry toilet, the woodwork involved and my system of minimal metal fixings which allows for movement of the planking and minimum costs. There are also updates and an alternative composting system for very cold climates:-

Pallet Wood Compost Bin and Dry Toilet Project Part 1

I opted for a completed bin size of 800mm x 800mm x  800mm, the wood used was recuperated from pallets.The unique design feature... read more

DIY Dry Toilet System for  8 Euros $11. Part 2 The Cabin

A practical design if you want to use this design for somewhere such as; your allotment, social garden, a field or even set up a business making them for others.... read more

DIY Dry Toilet System for  8 Euros $11. Part 3 The Seats

The toilet seat is for the ‘two bucket’ system. One side is for collecting liquid and the other is for solids...read more

DIY Dry Toilet System Part 3 The Seats continued

Continuing the above project with fitting out the interior...read more

Composting Urine Using a Straw Bale. Dry toilets for all climates.

A great way to process dry toilet liquid for around 6 Euros or 5 Dollars worth of materials... read more

Humanure - Two Years of Living with our Dry Toilet

Humanure is like death and taxes it's something we all know about but as the elephant in the room, are most loath to mention it...read more

Thanks for dropping by and please feel free to share this article, comment, ask questions and if you'd like to be assured of getting the next post, then sign up to follow this blog.

All the best, Andy

© Andy Colley 2014

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