Anyone clued up on woodburning stoves?
Discussion
Hi, I'm going to be fitting a freestanding, cast iron wood burner into my house here in Mallorca (Yes it does get cold and wet!)
I've done a total reform of the house, so it's well insulated, and draught free.
Here lies my question....a nice warm log fire is going to consume oxygen, so if my house is nicely sealed up, where's the air going to come from?
Do I need say, an air brick below the stove, which is against an ouside wall, to be able to feed the fire with fresh air?
And what is the minimum hight I need for my chimney? My house has quite a low roof where the stove will be situated (2.4 meters from the floor inside) but the back of the house has the highest part of the roof at about 3.6 meters. Does the chimney outside need to go up higher than the highest point of the roof?
Am I correct in thinking a taller chimney will draw better?
I've asked the suppliers of the stove, but they just do that Spanish shrug of the shoulders, with upturned palms thing!
Advice much apreciated,
Cheers,
Mick.
I've done a total reform of the house, so it's well insulated, and draught free.
Here lies my question....a nice warm log fire is going to consume oxygen, so if my house is nicely sealed up, where's the air going to come from?
Do I need say, an air brick below the stove, which is against an ouside wall, to be able to feed the fire with fresh air?
And what is the minimum hight I need for my chimney? My house has quite a low roof where the stove will be situated (2.4 meters from the floor inside) but the back of the house has the highest part of the roof at about 3.6 meters. Does the chimney outside need to go up higher than the highest point of the roof?
Am I correct in thinking a taller chimney will draw better?
I've asked the suppliers of the stove, but they just do that Spanish shrug of the shoulders, with upturned palms thing!
Advice much apreciated,
Cheers,
Mick.
Hi Simpo, thanks for your reply.
I'm not really concerned about rules and regulations, I'm more concerned about it working well.
There are regulations here, in fact you need a licence to do anything, even to fit a new kitchen! And you can't do it yourself (Officialy
)
It's because you have to pay the town hall for the licence, and then pay a tax to the town hall for the work that's been done, for the "inpector de Obras" to sign it off afterwards, although most of the time he doesn't bother coming to see it.
All has to be done by a "Constructor" but you're right, the quality is shyte!
As with most things in life, there's a way around it, hence I've done most of the work myself. But I did manage to get a licence.
Goes against the grain a bit to knock a hole in the wall, when I've worked hard to keep out draughts!
I'm not really concerned about rules and regulations, I'm more concerned about it working well.
There are regulations here, in fact you need a licence to do anything, even to fit a new kitchen! And you can't do it yourself (Officialy
)It's because you have to pay the town hall for the licence, and then pay a tax to the town hall for the work that's been done, for the "inpector de Obras" to sign it off afterwards, although most of the time he doesn't bother coming to see it.
All has to be done by a "Constructor" but you're right, the quality is shyte!
As with most things in life, there's a way around it, hence I've done most of the work myself.
But I did manage to get a licence.Goes against the grain a bit to knock a hole in the wall, when I've worked hard to keep out draughts!
mickrick said:
Hi, I'm going to be fitting a freestanding, cast iron wood burner into my house here in Mallorca (Yes it does get cold and wet!)
I've done a total reform of the house, so it's well insulated, and draught free.
Here lies my question....a nice warm log fire is going to consume oxygen, so if my house is nicely sealed up, where's the air going to come from?
Do I need say, an air brick below the stove, which is against an ouside wall, to be able to feed the fire with fresh air?
And what is the minimum hight I need for my chimney? My house has quite a low roof where the stove will be situated (2.4 meters from the floor inside) but the back of the house has the highest part of the roof at about 3.6 meters. Does the chimney outside need to go up higher than the highest point of the roof?
Am I correct in thinking a taller chimney will draw better?
I've asked the suppliers of the stove, but they just do that Spanish shrug of the shoulders, with upturned palms thing!
In the UK the regs are something like if you have more than an 8Kw stove you must have an outside vent in the same room to allow air in. In practise that can be anywhere in the room but obviously that can create draughts so the best place to put it is, as you suggest, right behind the stove or in the floor to the side of if you have a suspended floor and a stove on legs. You might need more than a simple air brick though (depending on how big the stove is).I've done a total reform of the house, so it's well insulated, and draught free.
Here lies my question....a nice warm log fire is going to consume oxygen, so if my house is nicely sealed up, where's the air going to come from?
Do I need say, an air brick below the stove, which is against an ouside wall, to be able to feed the fire with fresh air?
And what is the minimum hight I need for my chimney? My house has quite a low roof where the stove will be situated (2.4 meters from the floor inside) but the back of the house has the highest part of the roof at about 3.6 meters. Does the chimney outside need to go up higher than the highest point of the roof?
Am I correct in thinking a taller chimney will draw better?
I've asked the suppliers of the stove, but they just do that Spanish shrug of the shoulders, with upturned palms thing!
With regard to the chimney, if you look at www.stovesonline.co.uk there is some stuff there about UK Chimney regs. No idea what the spanish equivalent might be. I think the basic principle you need to look at is to make sure the top of the chimney is high enough so that smoke/fumes can't blow back inside your house (via a window etc) or get into your roof space via soffit vents etc regardless of which direction the wind comes from.
Edited by Iain328 on Saturday 9th January 15:25
Thanks for the replies. What else can I use then, if an airbrick isn't enough?
I was thinking of maybe a 4inch hole at floor level behind the stove. (The stove is on legs) or do you think I should make it higher, say behind the stove where it can't be seen?
It won't look bad outside, as I can put a nice terracotta grill over the hole, as I have done with the holes in the walls I had to make, to make a breathable airspace with my false ceilings. (Roof is concrete)
The foor is also concrete by the way. (I've installed hot water underfloor heating).
I tried to buy my stove from Stovesonline, as I see on thier website, they send a lot of stoves to Spain, apparently. I don't know how anyone manages to do business with them. But that's another story!
I was thinking of maybe a 4inch hole at floor level behind the stove. (The stove is on legs) or do you think I should make it higher, say behind the stove where it can't be seen?
It won't look bad outside, as I can put a nice terracotta grill over the hole, as I have done with the holes in the walls I had to make, to make a breathable airspace with my false ceilings. (Roof is concrete)
The foor is also concrete by the way. (I've installed hot water underfloor heating).
I tried to buy my stove from Stovesonline, as I see on thier website, they send a lot of stoves to Spain, apparently. I don't know how anyone manages to do business with them.
But that's another story! If Stove is 5kw or below it doesn't need an outside vent.
From stoves online.
"If the stove has an output of more than 5kW then it is recommended that dedicated permanentently open ventilation be installed with a cross sectional area of at least 550 square mm for every kW above 5. However if your house is very old with windows and doors that are not air tight then this may provide sufficient air for the stove, even if it is above 5kW. Please be aware that changes to the building at a later date will effect this supply of air. This means that it is good practice to fit dedicated ventilation for stoves over 5kW even if the stove has sufficient air supply at the time of installation. If your house is very modern with sealed doors and windows then dedicated ventilation may be needed for stoves under 5kW.
The vent should be placed in such a way that it cannot be easily blocked and so that house residents are not tempted to block it off to reduce draughts or noise.
It can be a good idea to place the vent close to the stove. Because the stove draws the air that it needs for combustion through the vent there will be a draught from the vent to the stove. If the vent is close to the stove then draughts are reduced and the house stays warmer.
If there is a mesh to guard against pest/mice etc coming through the vent then the mesh size must be no less than 5mm."
From stoves online.
"If the stove has an output of more than 5kW then it is recommended that dedicated permanentently open ventilation be installed with a cross sectional area of at least 550 square mm for every kW above 5. However if your house is very old with windows and doors that are not air tight then this may provide sufficient air for the stove, even if it is above 5kW. Please be aware that changes to the building at a later date will effect this supply of air. This means that it is good practice to fit dedicated ventilation for stoves over 5kW even if the stove has sufficient air supply at the time of installation. If your house is very modern with sealed doors and windows then dedicated ventilation may be needed for stoves under 5kW.
The vent should be placed in such a way that it cannot be easily blocked and so that house residents are not tempted to block it off to reduce draughts or noise.
It can be a good idea to place the vent close to the stove. Because the stove draws the air that it needs for combustion through the vent there will be a draught from the vent to the stove. If the vent is close to the stove then draughts are reduced and the house stays warmer.
If there is a mesh to guard against pest/mice etc coming through the vent then the mesh size must be no less than 5mm."
mickrick said:
Thanks for the replies. What else can I use then, if an airbrick isn't enough?
I was thinking of maybe a 4inch hole at floor level behind the stove. (The stove is on legs) or do you think I should make it higher, say behind the stove where it can't be seen?
It won't look bad outside, as I can put a nice terracotta grill over the hole, as I have done with the holes in the walls I had to make, to make a breathable airspace with my false ceilings. (Roof is concrete)
The foor is also concrete by the way. (I've installed hot water underfloor heating).
I tried to buy my stove from Stovesonline, as I see on thier website, they send a lot of stoves to Spain, apparently. I don't know how anyone manages to do business with them. But that's another story!
The location of the outside air vent does not appear to be critical as long as it is in the same room - so put it where you like more or less. You should be able to find some kind of grate that you can close for when the stove is not in use I would have thought. As suggested put a grill over the outside to stop insects & mice etc.I was thinking of maybe a 4inch hole at floor level behind the stove. (The stove is on legs) or do you think I should make it higher, say behind the stove where it can't be seen?
It won't look bad outside, as I can put a nice terracotta grill over the hole, as I have done with the holes in the walls I had to make, to make a breathable airspace with my false ceilings. (Roof is concrete)
The foor is also concrete by the way. (I've installed hot water underfloor heating).
I tried to buy my stove from Stovesonline, as I see on thier website, they send a lot of stoves to Spain, apparently. I don't know how anyone manages to do business with them.
But that's another story! I have spoken with the guy at SoL on a couple of occasions. I actually think he works on his own - but he seems to know his stuff. If nothing else you can get a lot of ideas & info from his website - but there are other people who sell Wood burners. Lastly, Suggest you consider a multifuel stove so that you can burn a bit of coal if the mood takes (or you run out of wood!)
I wonder why stoves don't have an 'inlet flue' that fits through the wall behind? That would provide fresh air straight to where it's needed, and no draughts in the room. A simple butterfly valve or shutter could be added for controllability.
Edited by Simpo Two on Sunday 10th January 16:22
Another hole in the wall it is then!Simpo Two said:
I wonder why stoves don't have an 'inlet flue' that fits through the wall behind? That would provide fresh air straight to where it's needed, and no draughts in the room. A simple butterfly valve or shutter could be added for controllability.
Some do - look out for 'room sealed' stoves, which are used in Passivhaus and similar schemes.Edited by Simpo Two on Sunday 10th January 16:22
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