Log burner

[Russ P]

My lounge is roughly 14sqm and I'm looking into having my chimney lined and a log burner installed. What KW burner would be sufficient? Or is there a website I could enter details on? Also anyone have any recommendations on burner brands i dont want a really modern style as it's a late 1800's cottage

[Crofter]

Ther are some calculators available online that give a rough estimate of required stove size, but they have to make assumptions about how well insulated your house is so are very rough guesses, really.

Stoves work best when they are running near flat out, so you want to size it for the expected heating requirement and not go for something too large. I've installed three different woodburners and none has been more than 5kw output; all have done a fantastic job of heating the rooms they were in. I installed a 5kw stove in a 18m2 living room and usually kept the double doors open to the equally large kitchen, as the heat was plenty for both rooms. This was in a house with pretty minimal insulation.

 

In terms of make/model, there is a surprisingly large range of variation. Key thing is the efficiency. Each stove I have installed has been of a higher efficiency, and you can tell from the design that more thought has been put into it. So my first one was from Aarow, and was pretty basic: sliding air controls, airwash taken from the front. Next was a Charnwood, which uses rotary air control which gives a far better seal, and which draws airwash air from the back of the stove, heating it in two tubes hidden within the stove. The result is preheated air blasting down the glass and keeping it spotless. Newest one is anothe step up again, a Burley which at 89% claims to be the most efficient available. Double glazed window, fully lined/insulated firebox, all air fed from an external source via preheating chambers within the stove. And it works- I have never had a stove that burns so hot, keeps so clean, and leaves so little ash. In fact I have yet to take any ash of out it at all.

 

The only downside of a high efficiency stove is that, because all of the heat is directed into the room, there isn't very much left to waste up the chimney. If your chimney struggles to draw, this can cause a problem.

[PeterW]

@Trw144 may be able to help you here with sizing etc. 14sqm is not that big so you may be limited to 4-5kw at best. 

[billt]

I'd echo what Crofter said; you want to run it with a hot fire to minimise pollution.

 

Assuming you don't have howling gales through the room or damp walls you'll probably find that the smallest stove that you can get will be enough.

 

We have 3 wood burners. The first one we installed in our lounge years ago is much too big for the room (22 sq.m.) I don't know what the output is but it's too much. The other 2 we installed are Franco Belge Belforts which were as small as we could find (upto 5.5 kW, and the looks suit our old house). The output is completely adequate for the rooms they are in, one 21 sq.m. and the hall which is 39 sq.m. At one time we were running the hall fire continuously while the main heating system wasn't working and it kept the chill off the house quite satisfactorily, although we were burning coal not wood in it at that time.

[Adsibob]

On 30/07/2017 at 18:51, Crofter said:

Ther are some calculators available online that give a rough estimate of required stove size, but they have to make assumptions about how well insulated your house is so are very rough guesses, really.

Stoves work best when they are running near flat out, so you want to size it for the expected heating requirement and not go for something too large. I've installed three different woodburners and none has been more than 5kw output; all have done a fantastic job of heating the rooms they were in. I installed a 5kw stove in a 18m2 living room and usually kept the double doors open to the equally large kitchen, as the heat was plenty for both rooms. This was in a house with pretty minimal insulation.

 

In terms of make/model, there is a surprisingly large range of variation. Key thing is the efficiency. Each stove I have installed has been of a higher efficiency, and you can tell from the design that more thought has been put into it. So my first one was from Aarow, and was pretty basic: sliding air controls, airwash taken from the front. Next was a Charnwood, which uses rotary air control which gives a far better seal, and which draws airwash air from the back of the stove, heating it in two tubes hidden within the stove. The result is preheated air blasting down the glass and keeping it spotless. Newest one is anothe step up again, a Burley which at 89% claims to be the most efficient available. Double glazed window, fully lined/insulated firebox, all air fed from an external source via preheating chambers within the stove. And it works- I have never had a stove that burns so hot, keeps so clean, and leaves so little ash. In fact I have yet to take any ash of out it at all.

 

The only downside of a high efficiency stove is that, because all of the heat is directed into the room, there isn't very much left to waste up the chimney. If your chimney struggles to draw, this can cause a problem.

@Crofter this is helpful, thank you. I'm looking for an environmentally friendly stove (appreciate that is an oxymoron, but I mean a least bad option) and so efficiency is probably key. I was considering the Nestor Martin range of stoves, such as a Nestor Martin TQ33 which has a "nominal rating", whatever that means, of 9kW.  This is quite big, but the stove is in an open plan area which is about 65m2 and almost 3m in height at some places, so it's quite a large area to heat. We won't rely on this necessarily as our heat source, but when it is on I don't want to have to have the UFH on as well. The house will be relatively well insulated, though not passive standards. Do you or @Trw144 have any experience of Nestor Martin.

And, @Crofter is your comment about a high efficiency stove making the chimney struggle to draw a serious concern? The original chimney breast of our 1930s semi has been knocked down, but we plan on keeping the actual chimney bit above the roofline (I think it's called the stack?) and connecting a brand new insulated flue pipe from it to the stove, which will be about 10m below. I could also add a new higher pot to the top get me another 40cm or so. It's a direct air feed setup as I'm going to have MVHR, but I've yet to finalise the design as I'm still learning. The current plan is to route the direct air feed pipe upwards into the room above and then out through an external wall, as that's the shortest distance to an external wall, even taking into account the two right angle bends I will have to take (so about 3.5m of tubing plus the two bends, means effectively 5.5m of direct air feed pipe, relative to about 10m of flue). Do you think the Burley would cope with that setup?

Edited April 8, 2021 by Adsibob

[Trw144]

8 hours ago, Adsibob said:

Do you or @Trw144 have any experience of Nestor Martin.

A little, we were the U.K. importer for 25 years and probably sold 100,000 + of them in one form or another. Great stoves - cast iron internals make them very durable, and they burn cleanly even when turned down low. Down side to this controllability is that you do need to know what the fire needs , so a little bit of learning to start with (ie. do you need primary air, secondary air, or both) I'm trying think back to the IQ33 - it was in development for about the 5 years prior to us exiting the market. The "plexus" control wasn't air tight at the time but they could well have worked on that since. At 9kW just check you can live with the output - stoves work better at a high output and you will much prefer to see a smaller output stove with a  window full of dancing flames than a big stoves turned down constantly.

Edited April 9, 2021 by Trw144

[Adsibob]

@Trw144 wow, you really are an expert then! Yes, apart from making sure it really is airtight, I need to work out if it is too big for my needs. It will be fitted to the side of an open plan area which is about 65m2 and almost 3m in height at some places. 7.5 metres in width and 9.5m in length at it’s longest point. The stove will go more or less at the mid point of the 9.5m wall.

 

What alternatives with a large window, but not such a large output would you recommend? Maybe something in the 7kw or 8kw size. This is a once in a lifetime purchase, so happy to spend a bit more to get the right thing.

[Trw144]

19 minutes ago, Adsibob said:

@Trw144 wow, you really are an expert then! Yes, apart from making sure it really is airtight, I need to work out if it is too big for my needs. It will be fitted to the side of an open plan area which is about 65m2 and almost 3m in height at some places. 7.5 metres in width and 9.5m in length at it’s longest point. The stove will go more or less at the mid point of the 9.5m wall.

 

What alternatives with a large window, but not such a large output would you recommend? Maybe something in the 7kw or 8kw size. This is a once in a lifetime purchase, so happy to spend a bit more to get the right thing.

Can you get the smaller version of it over here? We were working on a TQ13 and TQH13 at the same time which would have used the 5kW internals. I think this would be plenty for this space.

 

What about something Scandinavian styled? Hwam, Scan, etc. I have to confess a vested interest as I am still involved with them but I am putting the Lohberger Nobilus in my next build. Room sealed, auto closing door, and the option of a leather top, and also a Hwam inset 30/55.

 

Edit - I have just looked and seen that Scan offer a similar looking stove to the Nestor Martin, but at a smaller output.

Edited April 9, 2021 by Trw144

[Adsibob]

3 hours ago, Trw144 said:

Can you get the smaller version of it over here? We were working on a TQ13 and TQH13 at the same time which would have used the 5kW internals. I think this would be plenty for this space.

 

What about something Scandinavian styled? Hwam, Scan, etc. I have to confess a vested interest as I am still involved with them but I am putting the Lohberger Nobilus in my next build. Room sealed, auto closing door, and the option of a leather top, and also a Hwam inset 30/55.

 

Edit - I have just looked and seen that Scan offer a similar looking stove to the Nestor Martin, but at a smaller output.

Very useful thanks @Trw144. The Hwam has some pretty cool features such as their autopilot feature that lets you set the temperature. Really very clever. I didn't understand this though: "All HWAM wood-burning stoves are convection stoves. This means that the wood-burning stove quickly emits heat after lighting.

The heat is transferred by a natural air current, and not by heat radiation. This results in a pleasant indoor climate and a uniform temperature throughout the entire room.

Another advantage is that the outer cap of the wood-burning stove does not become especially hot. This is to say that furniture can be placed quite close to the wood-burning stove." Does this mean it pumps hot air into the room? Wouldn't that mess with my MVHR? If i have misunderstood that and it is indeed compatible with MVHR, then both the HWAM 4520 and 4620 models look that they might work well for my room; I just need to figure out how mank KW i really need, as the 4520 is rated 3-7kW and the 4620 is rated 3-9kW.

[Trw144]

1 hour ago, Adsibob said:

Very useful thanks @Trw144. The Hwam has some pretty cool features such as their autopilot feature that lets you set the temperature. Really very clever. I didn't understand this though: "All HWAM wood-burning stoves are convection stoves. This means that the wood-burning stove quickly emits heat after lighting.

The heat is transferred by a natural air current, and not by heat radiation. This results in a pleasant indoor climate and a uniform temperature throughout the entire room.

Another advantage is that the outer cap of the wood-burning stove does not become especially hot. This is to say that furniture can be placed quite close to the wood-burning stove." Does this mean it pumps hot air into the room? Wouldn't that mess with my MVHR? If i have misunderstood that and it is indeed compatible with MVHR, then both the HWAM 4520 and 4620 models look that they might work well for my room; I just need to figure out how mank KW i really need, as the 4520 is rated 3-7kW and the 4620 is rated 3-9kW.

Yes the Hwam's are great - opposite of a Nestor Martin in so much as the autopilot does all the controls for you (primary/secondary air), but at the expense of being less controllable in terms of output  (you wouldn't keep it in overnight for instance). The 4000 range is a very nice stove (used to have one in the showroom) and I think about 6/7kW nominal so more akin to your needs I would think.

 

The convectors heat is channels around the body and top of the stove - not so much forced heat but natural air movement from hot air circulating (rising).

Edited April 9, 2021 by Trw144

[PeterW]

+1 to Hwam and @Trw144 knows why .... absolute things of beauty and they work superbly. If you have budget then go for one - they are just beautifully engineered and a real quality piece of kit. 

[gdal]

Dear  @Trw144

 

Just wonder if you have a view on the Burley Brampton stoves? I have one in my current house and would I think get one in the new/renovated house. They claim very high efficiency (I think 84%) and in practise we get very little ash. It is beautifully controllable with a single lever, and I am very pleased. But I also know that it is 6 or 7 years old and technology and legislation moves on . . .

[Trw144]

4 hours ago, gdal said:

Dear  @Trw144

 

Just wonder if you have a view on the Burley Brampton stoves? I have one in my current house and would I think get one in the new/renovated house. They claim very high efficiency (I think 84%) and in practise we get very little ash. It is beautifully controllable with a single lever, and I am very pleased. But I also know that it is 6 or 7 years old and technology and legislation moves on . . .

Hi, I can't say I know much about them or have ever used one to be honest so could nt comment either way. As a genera point. I would take most stove efficiencies with a pinch of salt - they are based on test lab conditions with perfect wood, on a perfect flue and most crucially someone who knows how to operate it. This latter reason is why Hwam developed the Automatic systems - it's the people operating the stove that generally cause it to burn incorrectly.

[Adsibob]

2 hours ago, Trw144 said:

... and most crucially someone who knows how to operate it. This latter reason is why Hwam developed the Automatic systems - it's the people operating the stove that generally cause it to burn incorrectly.

I see that Hwam's stoves come with a "semi autopilot" system as standard and then you have to pay an extra £600 or so to upgrade to the fully automatic version, which gets you the temperature sensor that links to your phone/wifi etc. I'm thinking the full autopilot partly takes out some of the old world beauty of a wood burning stove, in that relying on your phone to message you when you need to load more fuel into the stove is a gizmo that just gets in the way of my idea of relaxing by the fire... ie phone off! We don't plan on running the stove every night. It will be more of a two nights a week kind of "special" thing for us.

In your recommendation @Trw144 were you referring to the semi autopilot or the upgraded with bells and whistles version?

[Trw144]

7 hours ago, Adsibob said:

In your recommendation @Trw144 were you referring to the semi autopilot or the upgraded with bells and whistles version?

To be honest I was referring to stoves in general - the Hwam is just the one I know with the automatic controls as an example (I'm sure others are available).  Talking specificallly of Hwam, the bi-metallic coil version works very well so I would nt be concerned about not going for the electronic version.