Stove Warm Air Heating

[Jez]

My OH and I got a small, old, broken woodburning stove from freecycle. Assuming we ever get it working, has anyone tried warm air heating their house?

Essentially it involves heating one room with a stove, and putting vents in walls and ceilings to circulate the air. See http://www.stovesonline.co.uk/stove-hea ... ution.html.

I suspect this may be hard to get right, and I also suspect you could end up over heating one room and underheating the next.

Any thoughts?

[Annpan]

I think that they did it in "Its not easy being green" but as far as I remember it was expesive and didn't really work.

Annpan

[Muddypause]

It's an interesting idea. IIRC, what they did on 'It's Not Easy...' involved an air extraction system, with a heat exchanger to capture some of the heat from the extracted air. This was then added to the incoming air to warm it up a bit. It wasn't, per se, a heating system, but it did move the heat about a bit.

You can still get warm air central heating systems. They were popular in cheap housing in the 60s and 70s, but people didn't really like them much; most of them have been replaced with a wet system. Modern versions of them are better, providing a strong blast of warm air to warm the place up with at first, and then maintaining the temperature with a steady trickle from then on. The main advantage is that it warms the air up very quickly.

Your idea would seem plausible, but I would have thought you needed a forced system, with some sort of fan to make the air move. I reckon that just relying on convection currents won't really get the job done. It would still need to be a carefully thought out system, and you would always need a return path for the air, back to where it started from.

Other issues that occur to me - well one wood burner providing a whole house is going to take a lot of stoking. Probably less, overall, than if you had separate stoves in each room, though. And it may be desireable to have ways of closing off rooms if you didn't want them heated. And temperature control may be tricky

[Jez]

Yeah, I can imagine. There seems to be a bit of a rip-off market around installing stoves. We've had quotes up to £3000. There seems to be a bit of a thing around chimney liners. Everyone will tell you you need your chimney lining, at cost of up to a couple of grand. However, my friend who is an engineer has looked into it, and a lot of the time it's just not necessary.

There's also an issue with building regs around amount of fresh air coming into the room, depth of floor, airblocks etc. However, in a draughty mid terraced late victorian house with well designed chimneys I'm not sure it's all necessary. Would value people's input on this.

I also suspect you need to heat your room with a stove in to furnace like levels for it to make an impact upstairs. Which is just not efficient.

[red]

yup there is a ne reg about air vents - and size of stove.. but i cant remember what it is.. just that its new

re the air flow thing - it would seem someone has tried to do that in my house - there are grills here and there.. but its not noticable.
my last house was more open plan - a knocked through living room dining room, adn the stairs were in the living room - so the woodburner warmed the whole house up - but that house had DG, pretty draft proof.
this house.. it seems the fire sucks cold air in!

when we light the fire it gets very hot in lving room with door closed. if we open door its freezing as there is a gale coming in under front door.
I would say the the vented heat system is best in a house without alot of drafts etc.

[Annpan]

sorry Red, I think I got confusled, It was quite a different system in INEBG.

This does look interesting though. - but I am a bit dubious as to whether it works. As you both say it does look like you would need it to get really in one room to get the heat to circulate. I think it would work quite well to heat the room directly above where the wood burner is, but I just don't buy the air flow around the house idea... its the kind of thing that works in theory but not in the real world.

I put another thread in "Green building" about heating a back boiler to run radiators. (sorry I put it on the wrong forum) As that is what we are wanting to do, and having looked in to it a little it looks promising - Bit more work involved though

Ann

[Clara]

The guy who built my cortijo tried this, just with open fire and vents (no forced movement of air) - it doesn´t even heat the room behind the chimney!

Though I once wwoofed on a farm in france where they had some kind of fan-propelled thing going on through those sort of flexi hose things you get on tumble dryers installed in the ceilings (sorry about the description - you know I´m a grower not a builder ) powered by an efficient modern stove. This worked well, had to use a loo roll to bung up the tubes when the rooms got too hot!

Clara x.

[eek]

You need to check into wood supply in your area also. How accessible, how expensive. I just read an article on pellet stoves that were all the rage when gas prices started going up. The demand for the stoves was high, supply was low, and the availability of pellets was iffy.

Now it costs more to have pellets delivered, if you can find them in your area, than it was to have gas or electric. Do you have wood on your property?

[camillitech]

[quote="Jez" There seems to be a bit of a thing around chimney liners. Everyone will tell you you need your chimney lining, at cost of up to a couple of grand. However, my friend who is an engineer has looked into it, and a lot of the time it's just not necessary

hi jez, i'm an engineer to and i thought just the same as your friend twenty years ago when i installed my first wood burner (a morso squirrel) which is still going strong. but trust me you do need a liner in most cases and once you get a metre above the stove it needs to be insulated honest! firstly if you don't line it at all the acids in the wood attack the morter in the chimney this weakens it considerably and the tar also leaches through causing unsightly stains (it happend to me) secondly if you just fit an uninsulated flue and don't keep your flue hot the tar will condense and go solid on the inside (it happened to me) i now have a flexible ss insulated flue which has been in around 15 years it cost me more than the stove but was worth every penny as it only needs cleaned every three or four years.

the flexible liners are great as you can push them round small bends etc in the chimney.

good luck paul

[Jez]

Grr, this whole issue is so complicated! And expensive...

Well, there goes my plan of a cheap heat source...

Wood around here is plentiful - we are right on the edge of square miles of chestnut coppice which is no longer being harvested. We got a half load for £80 which has done us the whole winter and will see us into spring - and that was an open fire. I think we was robbed - I'm sure we can get it cheaper. I wouldn't consider using anything other than wood.

[red]

i think there is a push to always have a liner but it is not always necessary - you can get your chimney surveyed by stove specialists.. in my last house they declared my chimney fine - this house we currently have an open fire and there is clearly a breach in the chimney as smoke comes out of two of the pots! - you can have the chimney repaired in a case like this - but a lining is the cheaper option - so basically its about how big and in what condition your chimney is in.

[camillitech]

i think there is a push to always have a liner but it is not always necessary - you can get your chimney surveyed by stove specialists.. in my last house they declared my chimney fine - this house we currently have an open fire and there is clearly a breach in the chimney as smoke comes out of two of the pots! - you can have the chimney repaired in a case like this - but a lining is the cheaper option - so basically its about how big and in what condition your chimney is in.

sounds like good advice to me

[teraivyyr]

Please can I bring this topic back from hibernation and ask for some advice?
Our house has an old woodburner in which needs replacing, just a little pot-bellied one, but last winter it was quite successful at heating the whole house. It helped that it's a tiny house, literally one room downstairs with the kitchen in the corner and the stairs going up the side, and upstairs two small bedrooms & shower room. (we have since added a conservatory at the back, west facing, which brings in lots of warmth when there is any sunshine.)
We are looking at getting a Morso Squirrel, which comes in a convection model, but have also looked at other stoves on which you can use a kettle or cooking pot. Anyone have any experience with either of these that they can share?

[red]

we got our woodburner installed this summer and its made locally here in Devon (i can pm details if you want). always get a flat top as yes you can boil a kettle or cook on the top

[Annpan]

We have just had a clearview 650 installed, it has a huge flat top, I can easily fit a few pots and a kettle on it.



Clearview make smaller models including one with an oven nook in it which I liked, and they are all made in Britain

You can also easily fit a boiler in it and it will do all of your hotwater too.