stoves with back boiler,does it make sense?

gooner

There are a lot of posts on here about stoves with back boilers.Mostly the route favoured is oil/gas boiler with a stove with back boiler backing it up.But if you don't have your own supply of timber or turf,does it really make economic sense.Surely if you have to buy your own fuel for the stove be it wood,coal or turf,then would it not work out more expensive than heating the house using the gas/oil boiler alone at Todays or even last Years prices.

I know that oil/gas supplies will deminish long term and the price will most likely go back up again,but I'm sure coal will go up in line with oil.Turf will probably get more expensive also as supplies deminish and further restrictions are placed on the harvesting of turf in certain areas of the country.As for wood,as the demand goes up it will probably also go up in price.

I would be interested to hear your opinions on this subject.

covey09

Yeah, there a great job heat the house and you'll have a nice cosy sitting room, plus they will take anything, make sure you have assess to the soot box though

gooner

covey09 wrote: »

Yeah, there a great job heat the house and you'll have a nice cosy sitting room, plus they will take anything, make sure you have assess to the soot box though

Thanks for the reponse.But which is more economical?

1. Oil/Gas boiler only

2. Oil/Gas boiler and stove with back boiler (fuel has to bought from a 3rd party)

My guess is no. 1, but I could be wrong.My point is that if you have to buy the fuel for the stove,then it's not the cheaper option.If you have your own supply of fuel then it is.Anyone?

Mellor

People attach an aesthetic quaility to the stove. Much like an open fire.
Depending on what you are burning, it might be slightly more expensive to use a stove. But it wont be huge, unless you use it alot. I'm getting one here soon, it will be cheaper for me, free supply of great quaility fuel

bamboozle

i'm hoping to grow a few willow trees down the back of the garden each year which should go a little way towards heating costs...

i havent mine installed yet but i believe one of the great benefits is that as the fire smoulders overnight it will still be providing some heat to the rads...

one of the other reasons we're going for one is aesthetics

RKQ

I agree Mellor.
If you light a fire and enjoy its colour and heat then fitting a back boiler is a good idea - as you'll be heating the water / rads at the same time.

A stove or insert will be more economical than an open fire. So if you light a fire daily its well worth installing.

If on the other hand you don't light or like an open fire - then stick to an oil or gas boiler!

Different strokes for different folks!:)

pool fan

why not put in a wood pellet stove with room heating and back boiler for rads and hot water?

gooner

Thanks for all the replies.The question was based purely on installing a stove with back boiler to contribute to the central heating.So I'm leaving out the fact that people like the look of an open fire or stove.If we base it on the fact that the stove will be installed solely to help with the heating and dhw.So it will be lit daily (be it all day in the case where the house is occupied during the day,or when the homeowner arrives home from work) and the hope would be that over the year it will cover a decent percentage of the heating and dhw demand and the oil/gas boiler will cover the rest.If we take it that the user doesn't have their own supply of wood or turf,so is in a position where they must buy all the coal,turf or wood.Where do we stand,is it now more econimical to to use the oil/gas boiler solely of a combination of the two?

Quazzie

I'd say a combination of the two because whereas oil and gas at the moment are relatively stable this is as proven before subject to vast variances in price. Oil at the moment is relatively cheap (believe it or not) due to our good stance in terms of exchange rates against the dollar and the pound but this could turn at any moment (admittedly not soon) and then oil will go back where it was. through the roof. Solid fuels are in comparison very stable price wise and if you make the stove compatible with home produced wood (fresh cut logs) then the price comparison will eventually even out and maybe in the favour of the combination.

I'd install it as it costs not a lot more initially, and you don't have to use it but it is a very handy thing to have, especially on weekends when the oil runs out on a friday evening, which seems to be typical.

Jupiterwood

Sounds a great idea ... but forget it unless you want trouble. The water jacket on a log burning stove will reduce the temperature in the firebox resulting in incomplete burning of the wood vapour.
So? Well along with being inefficient this will lead to an increase of tar and cresote build-up in your stove and chimney.
For wood to burn efficiently with low emissions it needs to burn at a minimum of 200C unfortunately as warter boils at 100C and for safety the water in your stove water jacket must be kept below boiling temp leading to inefficient burning of the wood.
The heat from wood is in the burning vapour and unfortunately the vapour will not ignite below 200C.

Some of the latest stoves offer an interesting option where the water jacket is removed from the firebox and instead is part of the flue pipe... again the temperature in the flue is an issue as a cold flue will result in the smoke/vapour condensing in your flue giving you that horrible tar build-up..

Forget the water get an efficient log burner room heater ... with preheated air , a cast iron door and convection heating. This will cost you a minimum of €1000 but you will never regret the purchase...

You can buy secondrate alternatives on ebay for around €400 - they work but generally the fire doors warp in very little time.

The second item you need to note is that you need dry seasoned timber. Softwood is no use !! full of tar and low heat value, birch and alder are ok but beech ass and oak are your best bet. You must stack in the open with cover from the rain but allowing the wind to blow through and you need to keep your logs like this for two years before burning.

Finally - your chimney / flue. If you have an old house you may need to line your chimney - you need a warm insulated flue for efficient burning . You can insert a flexible flue liner down most chimneys ,seal both ends and for a reasonable cost €500 you will heve an efficient chimney. The flexible liner comes in a number of grades and you will need a double skinned liner suitable for solid fuel burning - you can buy on-line and ship from uk for half the price you can purchase here.... They will deliver to your door ....

Best wishes

gerry28

Jupiterwood wrote: »

Sounds a great idea ... but forget it unless you want trouble. The water jacket on a log burning stove will reduce the temperature in the firebox resulting in incomplete burning of the wood vapour.
So? Well along with being inefficient this will lead to an increase of tar and cresote build-up in your stove and chimney.
For wood to burn efficiently with low emissions it needs to burn at a minimum of 200C unfortunately as warter boils at 100C and for safety the water in your stove water jacket must be kept below boiling temp leading to inefficient burning of the wood.
The heat from wood is in the burning vapour and unfortunately the vapour will not ignite below 200C.

Some of the latest stoves offer an interesting option where the water jacket is removed from the firebox and instead is part of the flue pipe... again the temperature in the flue is an issue as a cold flue will result in the smoke/vapour condensing in your flue giving you that horrible tar build-up..

Forget the water get an efficient log burner room heater ... with preheated air , a cast iron door and convection heating. This will cost you a minimum of €1000 but you will never regret the purchase...

You can buy secondrate alternatives on ebay for around €400 - they work but generally the fire doors warp in very little time.

The second item you need to note is that you need dry seasoned timber. Softwood is no use !! full of tar and low heat value, birch and alder are ok but beech ass and oak are your best bet. You must stack in the open with cover from the rain but allowing the wind to blow through and you need to keep your logs like this for two years before burning.

Finally - your chimney / flue. If you have an old house you may need to line your chimney - you need a warm insulated flue for efficient burning . You can insert a flexible flue liner down most chimneys ,seal both ends and for a reasonable cost €500 you will heve an efficient chimney. The flexible liner comes in a number of grades and you will need a double skinned liner suitable for solid fuel burning - you can buy on-line and ship from uk for half the price you can purchase here.... They will deliver to your door ....

Best wishes

Interesting post. What do you think of using coal instead of wood or a mixture of both?

beyondpassive

Have an AArow stratford SEB 20 Ecoboiler Stove installed, wee little thing with good output to the room and heats 6 rads and a cylinder coil. I thik its 6kW` to the room and 13kW to the water. Insulated the stones out of the roof and north and east walls and made it airtight to ensure the load is reduced. Its backed up by a second hand oil boilerwhich was lyin around, just for days we don't want to put on the fire. The system has more control than the starship enterprise, plumber was excellent. Surprised though by the number of pumps and interlocks. Still have to clean the ash, i had heard that there is minimal ash. Burning wood and rafter off cuts, with turf to slow the burn.

CJhaughey

Jupiterwood wrote: »

The second item you need to note is that you need dry seasoned timber. Softwood is no use !! full of tar and low heat value, birch and alder are ok but beech ass and oak are your best bet. You must stack in the open with cover from the rain but allowing the wind to blow through and you need to keep your logs like this for two years before burning.

I have to disagree, softwood is fine to burn once properly seasoned and burned hot there is ano problem with creasote buildup.
I have burned pine for many years and have never had any more trouble than from other woods.
Granted it burns fast but that is actually good thing in the early autumn and late winter when you don't need a long burn.
I do agree that that all wood should be seasoned before use otherwise you are simply wasting heat driving the moisture from the wood before it burns.

Gripen

Also, just to add to the discussion, how much coppiced willow/any other suitable type would you need to plant, ie what acreage? to keep your stove going for the year? Lets say it's for a 1500sqft house.

CJhaughey

Gripen wrote: »

Also, just to add to the discussion, how much coppiced willow/any other suitable type would you need to plant, ie what acreage? to keep your stove going for the year? Lets say it's for a 1500sqft house.

All depends on your house insulation/efficiency and your tolerance for cold.
Some houses mught burn 2 cord a year, others only half.
You need to be more specific.

10-10-20

Gripen, give us the total gas or oil consumption for the year for your house and I can estimate the equivalent input in wood Kg's.

Leadership

Gripen wrote: »

Also, just to add to the discussion, how much coppiced willow/any other suitable type would you need to plant, ie what acreage? to keep your stove going for the year? Lets say it's for a 1500sqft house.

I have been looking into the same for a while now and spoke with various "experts" from here and abroad. For my home which is 2500 sqft but well isulated I need about 4-5 tonnes a year of seasoned timber to burn to be self sufficiant. How many cords is depandant on the mass of the timber as all seasoned timber has the same calaorific value but different mass. As I will have lazy days and use the backup oil boiler my estimate is I will use about 3-3.5 tonnes a year. My next choice was the type of trees I will coppice and I am going for a 4 year cycle for ash, beech and birch for local reasons.

Long story short after all those factors I need 2 acres but I will plant on 2.5 acres initially to see how I get on.

10-10-20

Leadership - that's a lot of manual lugging of wood. I'm asking this because I'm interested to know how this works on a small scale, but how do you plan on managing this? I assume you'll have a ventilated shed for seasoning & drying, and a log cutter/splitter etc.
Are you going to replant each year with a 4 year growth cycle?
What's the estimation in terms of work-hours per year?

Gripen

I don't have a house built yet I'm just casually researching so haven't any figures on the oil side of things to compare. You wouldn't need to replant if you coppice the tree ie cut it back to ground level it regrows in handy stools for cutting fairly quickly.

Jupiterwood

Have a look at video of woodburner operating at 250C , you can see it burning the vapor. This is a Varde stove costing around €1800. Also note totally clean glass and no tar on firebricks...

http://www.youtube.com/watch?v=-Fs_hR1N0ww