Wood pellet boiler sited in detached garage

[Steve Smith]

Hi all. I am after some advice please. We plan to replace our heating system in a major house refurb next year. We are not in a mains gas area, currently we have an uninsulated house with very expensive LPG heating. I am looking at maybe using wood pellet heating, but these boilers are large and require a big store of pellets to be quite adjacent. We plan to have a garage sited

5m from the main house so if we put the boiler in the garage we would be running approx 7m to the house with 5m under exposed ground. Does anyone have any idea of heat loss to expect from this? In the US boiler houses are quite common I believe but in the UK boilers seem to only be sited in the main body of the house.

We plan to clad the house which has solid 10"walls (approx 100 years old) with EZClad insulated brick slip system to ground floor top of window height and then insulated battened vertical tiles to the roof. We will also be insulating the roof and double glazing all windows, after which I calculate we will need a 20KW boiler system. We will also be adding a small celcon extension. Has anyone any experience of I-Beam TJI floor joist systems too? We think they may be the best solution for the 1st floor floors with celcon floors for the ground floor. really we are almost rebuilding the house!

Look forward to any comments.

Steve

[Christian McArdle]

Is there a reason you haven't considered oil? It is typically what is used when mains gas is not available.

Christian.

P.S. Keep the LPG system as well, for the cooker.

[IMM]

That is because we are all rammed inside very small houses.

This house needs as much insulation as possible. Have Kingspan isnulation between teh batons and insulated tiles over.

Minimum 300mm of Rockwool. Also make sure all the cracks are sealed in the house. That includes and pipes and cables that enter the loft.

Make sure this is super insulated, so you don't need heating in the extension. The extension may reduce heat loss in the main building overall too.

They are the buiness. They are becoming the norm now as the main developers are using them

Is the ground floor solid? If so dig down at the side of the external walls about 1 metre and install Jablite insulation against the foundations up to ground level. This greatly reduces thermal bridging to the cold earth around the sides of the house.

Concentrate on the insulation, thermal bridging and air-tightness. Get the fuel usage down and then running an LPG boiler will not be so expensive. The money spent on a wood stove could be used to greater effect elsewhere in the house to reduce heat loss. Also insulation keeps a house cool in summer.

[The Natural Philosopher]

I actually agree wih this.

so far having sorted all teh little draughts out, the hose is running entirely of an aga for heating and an open fire, plus wasted heat from electrical stuff, and its not small (the house).

However I think that given the oil situation, a wood burning furnace migt not be a bad idea.

If oil becomes temporarily unobtainable, I can just about keep going with wood stoves and open fires, and the trusty chainsaw.

[Andy McKenzie]

A wood fired, steam powered, chainshaw I trust, in the temporary absence of oil?

;->

Andy

[Dave Liquorice]

No a cordless one and a bicycle generator...

[Neil Jones]

Wow - you can get a machine that generates bicycles? Where can I get one?

[The Natural Philosopher]

Nah, keep a few cans of petrol to tide me over tight spots...

[The Natural Philosopher]

its called Cambridge Student Population.

Come on over and pick one up.

Everyone else does.

[IMM]

Do you mean the snots seal bicycles? Typical, they steal everything else.

[Neil Jones]

That's why they're called tab bastards.

[N. Thornton]

Insulating has been mentioned.

Re double glazing I presume sure youre aware of the question mark over them ever paying their cost back in savings.

Draughtproofing I dont much like myself, health comes first for me.

But there is one trick that might interest you. It is not difficult to make a wood powered heater that delivers hot air into some open or communal area in the house. It is basically just a brick built closed furnace attached to the back of the house (or wherever), with a basic metal heat exchanger, big enough that it will take 4' or 6' logs. This would burn wood, greatly reducing the lpg bill, but without the cost of buying a wood pellet burner.

The size means most waste wood can just be dropped in whole: tree trunk sections, pallets, whatever.

If you build it so its partially inside the house, you can add metal cooking plates to it and you have an aga type arrangement.

Another plus with long logs is that you can burn them at one end, and the fire will move along the wood over time, giving you a long burn time.

NT

[The Natural Philosopher]

Its teh non university students who nick them. The old tech college - sorry 'university of East Anglia' etc.

[Steve Smith]

Thanks for that, and thanks to everyone who answered. It does seem that the key is insulation, insulation, insulation! I have been looking at the Knauf product line, they do polyfoam boards or rockwool based boards for thermal insulation under vertical tiling, seems to be the biz. Update on wood pellet systems shows that as we are in a Smoke Control Area, only one boiler would be ok to install,

so that seems to be a no. The other green option is a ground source heat pump system, as we will be excavating anyway this may be a good idea. Cheers, Steve

[N. Thornton]

if youre excavating be sure to put an earth pipe in! Costs peanuts and gives you very low energy use a/c all summer :)

NT

[IMM]

Heat pumps are very expensive. to install. The running cost is approx the same as a gas condensing boiler. In summer they may not raise enough heat for DHW purposes meaning you will have to supplement with an immersion heater.

Yes insulation, insulation and air-tightness is the key. Spend most of your money on that.

[Pete C]

Yes, for natural gas. If the OP had natural gas I doubt they'd be on LPG and considering a wood pellet boiler...

Could worth putting in a ground loop for future use if excavation is being done, in a few years they may reach a more attractive price point, and/or CO2 heat pumps may be able to run rads and DHW,

cheers, Pete.

[Rob Graham]

This is a nice idea and I'm sure in some circumstances it would work, but getting wood for burning is now beginning to become less easy with the general encouragement for woodlands to be left uncleared to allow nature to do the recycling. The other factor is that wood burning does require a lot more effort in total - collecting, storage, cutting, drying, stove loading, ash removing, etc.

I can sympathise with the wood chips idea. As for running the heatng pipes under the ground I can only suggest that this is doe in a lot of industrial situations and just requires a lot of insulation. I would have thought a brick lined channel would be the solution.

Rob

[N. Thornton]

It does, thats its main problem. At least some of those can be reduced or eliminated with sensible design. One can stop and have a word with any rip-out projects, telling them youll take all their scrap wood free if they give you a call and come dump it, it saves them the dumping costs. Also a word with places that produce lots of wood offcuts. These can give you free wood, and sometimes will deliver it for you.

Storage hassle can be minimised by dumping the wood in an enclosure rather than stacking it.

Drying happens by itself in a covered enclosure next to the furnace.

Cutting is eliminated with a large stove that will take pieces upto whatever your size limit is, 4', 6', 8'. No need to cut also means that nails in scrap wood are a non issue.

Stove loading: yep, you got to do that each day.

Ash removal, thats nedeed but the frequency drops with a large capacity stove.

So I agree its a pain compared to gas, but it will suit a minority of folk, and is basically free heat. It is more interesting for bigger blocks of flats where the money saving adds up to enough to pay someone for a small amount of time to run the system.

A lot of energy in the form of wood is going to waste at tips, it could be used to heat large complexes.

NT

[IMM]

Oh snotness of it! The petty snobbery is all too apparent. The snots do the nicking.