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Heating, what if not a wood burner?


JohnRoss
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I would very much welcome the opinion and advice of members in connection

with heating our house. At the moment we have had a wood burning Supra Stove

with an electric turbo fan as the main source of heating and additional heating

provided by paraffin stoves and electric wall panel heaters or electric fan

heaters. The Supra has been adequate in Winter and the paraffin and electric

heaters have only been needed first thing in the morning and during cold spells

in Spring and in Autumn when we have not lit the wood burner.
 

Last year I wrote about an incident when there was a small fire in the

tubes coming out of the back of the wood burner and yesterday we got really

scared when there was a fire again in these tubes of sufficient ferocity to make

us consider calling the fire brigade and get our cats into their transport

baskets to quit the house. Fortunately it was got under control by closing the

stove air intake vent at the bottom and also closing the valve in the tube

rising up from the back of the stove to the liner in the chimney. Took about an

hour to stop smoking. I say ferocious as there was thick smoke pouring out of

the chimney pot and loud roaring and crackling in the tubes feeding the

liner.
 

I opened up the stove and moved it out of the way so I could sweep the

chimney today. The tubes at the back of the stove were encrusted with light

tarry looking lumps of black material and on putting the brush right up the

liner the stuff that fell down was similar to that described above. I had a

sweep in this year at the beginning of the heating season to get a certificate

and the soot removed looked normal, i.e. grey/black and powdery. I swept the

liner again just after Christmas with the same result, grey/black powdery soot.

In past years we have never had so much of what I assume is cakes of creosote sooty stuff

like I saw today other than the little bit that caused a minor fire last year. The wood we burn is supplied by a local chap and looks no

different this year to previous years. One thing I did not do this year is burn

a chemical log a week or so before sweeping, I just forgot, and maybe this is a

factor! In the past I have burnt a chemical log at least twice during the season

before sweeping.
 

Frankly whilst a nice log fire is good to look at I am beginning to think

that the disadvantages like dust produced by the fire and the threat to our

security outweighs the advantages like low fuel costs compared with other forms

of heating. Carting the logs from the barn ain't fun either when it is

cold.Typically about 450 euros/year for 10 steres of wood being split logs. So

what do you suggest folks? At the moment I am thinking something like a large

Nightstore/Accumulateur for background heat and maybe something like a heat pump

device. Our supply rating is only 9kW so electric heating has to be limited to

leave a margin for other needs like cooking. So if you have dumped wood fires in

favour of something else your input would be much

appreciated............................JR
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I would dump the Supra, well sell it on Le B C at least, there are loads of suckers out there who will buy it judging by the number of people who defend these fires on the forums.  Then with a bit more money added to the sale price buy something really good that combusts properly burning the gasses that are causing your tar deposits.  Something with a fire brick lining and super heating of the incoming air to really extract the maximum from the logs you burn.  Oracle has a system I saw some pictures of recently with a big heat store and Solar + wood burning boiler I believe.
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I wouldn't be in too much of a hurry to dump the Supra. It is a well-respected make, and I don't think it's the stove that's at fault.

I've had this problem with the "creosote" deposits. It's a combination of factors which causes the problem, but basically the wood is not being burnt sufficiently hot enough. You need to run the stove for at least half an hour a day on "full blast" so that the flue liner gets hot all the way to the top. It also depends on whether the flue runs up and exsisting chimney, or up an outside wall, and whether the flue liner is twin-walled steel (which is better), or a single skin. If the flue is in a cold airspace it promotes condensation which is where the tar forms.

You may also want to check the size (diameter) of the flue; is it big enough? A small single skin pipe (125mm for instace) will clog up quickly under these conditions. The stove manufacturer will specify the minimum flue size (often 180mm or more). And it shouldn't have nasty right-angled turns.

I haven't had a flue or chimney fire, and it must be frightening, but you did the right thing, closing the air supply cuts off the oxygen feeding the fire. The roaring noise is the tar/creosote deposits on fire and sucking in more air from the bottom. It can damage the liner though. Imagine how bad it would be if it was an open fire and an old chimney with a brick or stone lining, you'd never control it!!

I now sweep my flue at least three times during the winter burning season, and I run the fire hot in the early part of the day. The wood burner is in fact too big for the size of the room, which is what encouraged me to run it continually low. I think when we look at these wood burners, a small one just doesn't look good enough for a cold winter, but my French friends here say that it's better to run a small stove fairly hot, than a large stove on a low setting. I do use the "bouches de ramonages" before sweeping, and for the past few years I've had no further trouble. I open the doors to all the other rooms if it gets too hot.

 

 

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JohnRoss

I agree with both of the above posters (to some extent).

Root of the problem is that the stove you have isn't being run hot enough and you are right to be concerned. When I see a stove fire smoldering away on slow combustion as many are want to do, I really fear for the consequences. Virtually without exception, stove fires need to maintain certain flue gas temperature to remain safe to use and so it’s a good idea to have a flue stat to know if its burning well or not. Saves a lot of effort and could save a catastophe.

On the system design side, all the Heating Engineers I know, have much the same mantra in that; once all the draught proofing and insulation has been taken care of, then the supply and distribution of the heat has to take form depending on the demand and the building layout. The bigger the house, the bigger the problem to make a single source of heat go everywhere. You say that you've got only 9kW supply which is not enough (but I'm no electrician) to run a decent size heat pump and the other appliances in your home at the same time. So you'd have to run it at night which defeats the purpose of buying a heat pump which is at its most efficient during the daytime higher temperatures. Once the Night falls to 0° C and below, then they are pretty well useless as an economical heat source... you may as well plug in a bar radiator.

Teapot was referring to my system which is a combi or multi source heat system with an accumulator. I get heat form a number of sources (solar, wood, electric, gas)when its economical to do so and then store it, then take it as I need it. It works for me.. I suggest that you talk to a heating engineer (not a salesman) to look into and decide what's best for you.

O

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For what it's worth - and I know little on the subject myself - the engineer who sorted out our fires in our English home said installers often don't pay enough attention to the chimney and flue design. Which I think he described as "technical art".
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Thanks for some thought stimulating replies folks. The Supra Orlando

Olliare was installed in the Summer of 2008. It replaced an older wood burner

which had a 200mm liner running up the chimney. The guy that installed the Supra

left the 200mm liner in place and pushed a flexible double skinned liner down

inside it and it was a tight fit. The house is quite tall and about 10 metres to

the top of the chimney. The installer did comment that he thought the liner was

a bit long and I guess this would imply an increased risk of condensation of tar

products further up the liner. I would have thought two liners might be better

than one when it comes to chimney fires!
 

I have no way of knowing how far up the liner the fire went but I could ask

the installer to come and examine, don't know how that could be done, and

replace if needed and if I could be sure he had not only self interest in doing

so!
 

It may be that it is significant that this happened in the one year that I

forgot to burn chemical logs. It may be that doing so in past years had

prevented this problem. I split my logs again after delivery using a small hydraulic log splitter but they are still

quite thick and up to 50cm long. I accept that small hot fires are better than

large smouldering ones and one site suggests that logs should be cut to fit fore

and aft rather than crossways. Would have to buy a power saw to try that!
 

What sort of power input is needed for air to air heat pumps? One site

suggests they should produce some useful output with an outside temperature as low as

-15C. I suspect from what has been said that that is being over optimistic! Our

wall panel heaters are measuring at a fraction under 2kW each and we have two of

them downstairs which is open plan of about 60 square metres. Maybe I could replace one with a 2kW Nightstore/Accumulateur

for general background heat but the main source of heating remains undecided.

Really don't want to be in such a scary situation again and I think we were dead

lucky that time. Equally I don't want to be in a situation of having to switch

something off in order to have enough power to cook lunch!................JR
 
PS It is looking like the fire in the liner was more than I had first thought as having wandered around outside today have found some clumps of very light tary looking foam on the ground around the house which must have been blown out of the chimney and I can see lumps of it hanging inside the flat top of the chimney pot thingy!
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We have 'inverter' air to air heat pumps as does another member Ulsterrugby. Ours have a 'COP' of around 3.6, that equates to 2.7kw of heat for 750W of power which is around 3.5A and they work quite happily down to -15 deg C. If you pay more for the same output you can get down to even lower temperatures. We had some quests from Finland (they can get temperatures down to -30) and they use them a lot there apparently although they are the more expensive high end versions. With all heat sources they are only as economical as the insulation of the house allows.
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Just to come back down to reality for a minute, you don't get a COP of 3. anything at those low temperatures.  The only unit I know of that goes that low is the Mitsubishi Zuba

If the Poelle engineer (loose term) Fitter, thought 10m was "a bit long" why not actually do something about it? Perhaps fitting a rotating cowl to give extra draw or even the electric extractors if needs be.

I still say Supra's are poor as they struggle to achieve 70% efficiency and despite lots of people sticking up for them they do not compare with more efficient manufacturers models at 80-85% efficiency and far better combustion of the tar and gases.  Well respected by whom, a load of people owning doesn't make them factually better and unless people can actually compare them to another stove the information is duff. The Sun is Britain's best selling newspaper, doesn't make it good though!

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We have Handol 'ollaire' stoves. They both burn well with very dry hard wood.

I'm surprised that the quality of the wood you are using has not been jumped upon. We had problems with our poele in France when we ended up with some soft wood. We knew that we had to have the fire burn hot, but we still had problems and frankly the only way that our poele was most efficient was with very very well dried wood and preferably hard wood.

What if not a wood burner? We have friends with under floor heating, both with types of heat exchange, one from a buried  heat exchange system and the other from a water source. They are happy enough although need extra heat when the winter is very cold.

Personally I would never have bought a Supra and yet I know plenty of people who have them. For all they looked nice, they never looked 'solid' I suppose, for want of a better word.

Burn your fire hot and good wood is all I can suggest.

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[quote user="JohnRoss"]Sounds interesting. Do you have a make or web site link I can have a look at?.............JR[/quote]

Not the model I bought from BricoDepot but there are no technical details on their website so the one below is about the nearest in power and price.

http://www.leroymerlin.fr/v3/p/produits/pompe-a-chaleur-air-air-pack-monosplit-zibro-s3025-2500w-e60379

Usng these have made a massive impact on my electricity bills.

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[quote user="idun"]I'm surprised that the quality of the wood you are using has not been jumped upon. We had problems with our poele in France when we ended up with some soft wood. [/quote]

What do they burn almost exclusively in Scandanavia (Sweeden) where I was, pine/spruce.  So It comes down to how they burn.

[quote user="Quillan"]

[quote user="JohnRoss"]Sounds interesting. Do you have a make or web site link I can have a look at?.............JR[/quote]

Not the model I bought from BricoDepot but there are no technical details on their website so the one below is about the nearest in power and price.

http://www.leroymerlin.fr/v3/p/produits/pompe-a-chaleur-air-air-pack-monosplit-zibro-s3025-2500w-e60379

Usng these have made a massive impact on my electricity bills.

[/quote]

At -10-15 you'll only be getting a COP of 1:1, each kw of electricity will produce a kw of heat. What makes these seem different is the forced convection from the fan unit circulating the warm air quickly, rather than  a Kw radiator that doesn't radiate very well or convect very well from a comfort perspective.  Of course you get the benefit of cooling in summer if required and better COP performance when it's not quite so cold. You must look at the technical data and performance graphs not the "look" of the item or the shop where you purchase or the silly "A" rating which is actually a "B" rating on heating.

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[quote user="Théière"]

I still say Supra's are poor.... [edited] ....  Well respected by whom, a load of people owning doesn't make them factually better and unless people can actually compare them to another stove the information is duff. The Sun is Britain's best selling newspaper, doesn't make it good though!

[/quote]

A poor analogy. The Sun must be doing something right (hard to see from here though); maybe people don't want to read long words or in-depth analysis first thing in the morning, maybe they only want the football results. Cost to the reader is one thing; I've never bought a copy of the Sun but I think it's about one third the price of a broadsheet, so that's one possible reason. The Sun is still going after nearly 50 years and has the largest circulation in the WORLD.  Supra are amongst the best-sellers in France and they're still going after 130 years (I just looked it up). I can't believe they'd survive that long flogging crap products. It's an entirely different matter buying a morning paper to laying out for a fairly expensive piece of domestic equipment.

Fact is the OP already has the woodburner, so he could save his money and simply change his way of burning the wood.

I think the OP probably wants a selection of views from people on here. Why does it always have to spiral into stupid argument?

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[quote user="Théière"]

At -10-15 you'll only be getting a COP of 1:1, each kw of electricity will produce a kw of heat. What makes these seem different is the forced convection from the fan unit circulating the warm air quickly, rather than  a Kw radiator that doesn't radiate very well or convect very well from a comfort perspective.  Of course you get the benefit of cooling in summer if required and better COP performance when it's not quite so cold. You must look at the technical data and performance graphs not the "look" of the item or the shop where you purchase or the silly "A" rating which is actually a "B" rating on heating.

[/quote]

The A rating is for cooling and in general the heating is B rated. As to a COP of 1:1 well I can't quite see that. Without getting in to claims of what the manufacturers make about their pumps, gases used etc I can tell you this. We have in the past used three sources of heating, wood, electricity and paraffin. We still burn the same amount of wood, about 4 to 5 cubic metres per winter. We have reduced our usage of paraffin heaters because the price of the paraffin has gone up so much in recent years from €16 per container to €26 on average.

Electricity usage on the other hand has dropped considerably. Our annual bill using 'radiators' which are half convection and half storage (which were claimed by the previous owner to be very economic) was around €2,300. Having installed these inverter units in place of the old heaters our annual bill has reduced to around €1,600 which I consider to be very good. I can't remember the exact figures but I did work them out last year and posted them on the forum, the 'payback' on the units would be very quick. Some will say that both these figures are high but we are heating around 163m2 and a third of that is in an area with a vaulted ceiling (never have one of those again, it gobbles heat). I also suspect if we traded exactly like for like it would be cheaper but there is a temptation in summer is to use them to cool rooms which we never did before. We don't have them cooling all the summer just occasionally. So all in all I consider them to be very economic and they do function below -10 OK as we normally have those sort of temperatures in winter over night and most mornings. This year the temperature has only gone down to -1 or -2, it has been very mild but very wet so we are hoping it will be an even cheaper year. So these figures are not 'claims' or guesses, these are actual from my bills and I can give them down to exact amounts including cents if you want.

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[quote user="JohnRoss"]

 So if you have dumped wood fires in favour of something else your input would be much appreciated............................JR

[/quote]

Sid

I think that most would agree that 'debate' (not argument) is what this forum thrives on, or if you would have it removed to the rest with the opinions of only a few then the forum will certainly fade into obscurity. Notice the OP quote where he is asking for peoples input - I think that is sufficient context for everyone to say their piece- don’t you?

I concur with Teapot insofar as this subject is somewhat technical in nature and the proliferation of misinformation or misguided viewpoints are unhelpful to someone like JohnRoss who after following 'a popular solution' finds that it doesn't suit him -he now wants to look at something different. The fact that you want to defend the original stove for whatever reason of your own is a moot point in my view - he said that it didn't suit him and he wants to look at something different.

So what is going to be an improvement.... well as has been amply demonstrated in the last pages, the idea of Heat pumps, whether they are air to air, air to water, or ground source has exploded in popularity over the last decade have suffer equally with the same sort of misinformation and mythology about what they can and cannot do. There is no heat pump so far invented that can create energy, that is simple fact. What they do is to exploit a temperature difference between the source temperature and refrigerant, compress it and deliver it. The only units which will give temperature difference below zero are filled with CO2 and are very expensive. So unless we are talking about a CO2 unit I'm afraid Teapot is right in that at the coldest time when you need the heat the most then the COP will be something like 1:1 which , as I said before is no better than a bar radiator. Pretending that it can be other than that is extremely unhelpful to those who are asking for guidance - because it’s just wrong. As I said before debate is good, but there must surely be a duty by all contributors to verify that what they post is not only valid but is also correct, example Quillian said “ it brought down her electricity bill" - fair comment and probably true, what was not at all true was the proposition that ‘the unit has a COP of 3 at minus temps’ - it doesn't.

I can post the details of plenty of these units with COP of 6 and above (at 24°C) and in the same sentence I would say that that will provide COP 3.8 at 15°C, these two numbers provide the buyer with the concept that as the source temps drop then so does the economic advantage. The only exception to this is effect where the source temps are constant such as ground sources, or subterranean water source – a system which is notoriously expensive to install.

I also agree with Teapot in the matter of the design of wood stoves, because in this day and age there is simply NO excuse for a stove to perform less than 80% efficient. For there is so much on the market which is better than that, with 90% or as much as 95%, that the decision to stick with 'the ol banger' is really only nostalgia and not at all common sense. Wood is expensive and takes some effort to process before its burnt, it may as well be burnt in a stove which will get the most out of it – to do anything else is wasting of resources which is by far the biggest scandal of this generation who certainly know better. There is no excuse.

 

 

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Théière said: What do they burn almost exclusively in Scandanavia (Sweden) where I was, pine/spruce.  So It comes down to how they burn.

We were given soft wood in France, pine maybe and it was supposed to be dried and we had clumpy black lumps forming and even tar around the joint in the foyer ferme. That was after using that fire for several years without any problems whatsoever and never any tar forming round the door..... what a nightmare that was to get rid of. I already knew that the fire had to burn hot etc and this stuff did. It didn't stop the problems. I wouldn't touch the stuff again.

Our current stoves are swedish made and we are recommended to burn very dry hard wood. Which we do.

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[quote user="Quillan"][quote user="Théière"]

At -10-15 you'll only be getting a COP of 1:1, each kw of electricity will produce a kw of heat. What makes these seem different is the forced convection from the fan unit circulating the warm air quickly, rather than  a Kw radiator that doesn't radiate very well or convect very well from a comfort perspective.  Of course you get the benefit of cooling in summer if required and better COP performance when it's not quite so cold. You must look at the technical data and performance graphs not the "look" of the item or the shop where you purchase or the silly "A" rating which is actually a "B" rating on heating.

[/quote]

So all in all I consider them to be very economic and they do function below -10 OK as we normally have those sort of temperatures in winter over night and most mornings. This year the temperature has only gone down to -1 or -2, it has been very mild but very wet so we are hoping it will be an even cheaper year. So these figures are not 'claims' or guesses, these are actual from my bills and I can give them down to exact amounts including cents if you want.

[/quote]

I didn't say they they didn't function at -10 unfortunately you have drawn the conclusion I was passing a comment on your system but I wasn't.  I have the information on Chinese manufactured models for warm climates and Scandinavian units for colder climates that still work and the coldest operating one for Canadian temperatures -30 (The Mitsubishsi). The efficiency (COP) drops to 1:1 at some point when it's cold enough so taking a face value Brico judgment is risky.

I have not laid claim or suggested guessing, again it is what you think I said.  The units have fans inside which blow the heat around so your 5kw of heat (@ COP 1:1 in -10 deg) is circulating around the room really nicely and makes you feel nice a warm whereas a 5kw bar fire or radiator would warm up only a small area around the heat source although consuming the same 5kw you would not feel anywhere near as warm.

Very sorry JohnRoss, but if you are going to spend any money on a system I am sure you would want that to deliver.

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[quote user="idun"]

Théière said: What do they burn almost exclusively in Scandanavia (Sweden) where I was, pine/spruce.  So It comes down to how they burn.


We were given soft wood in France, pine maybe and it was supposed to be dried and we had clumpy black lumps forming and even tar around the joint in the foyer ferme. That was after using that fire for several years without any problems whatsoever and never any tar forming round the door..... what a nightmare that was to get rid of. I already knew that the fire had to burn hot etc and this stuff did. It didn't stop the problems. I wouldn't touch the stuff again.

Our current stoves are swedish made and we are recommended to burn very dry hard wood. Which we do.

[/quote]

It's a similar content to the swimming pool threads, Poolguy and I going on and on about testing levels. Who has a moisture meter for their wood?  Not having one could lead to a house fire, small price to pay and it may well mean not having to sweep the chimney as much if you burn wood with the correct moisture level.

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[quote user="Théière"]

I didn't say they they didn't function at -10 unfortunately you have drawn the conclusion I was passing a comment on your system but I wasn't.  I have the information on Chinese manufactured models for warm climates and Scandinavian units for colder climates that still work and the coldest operating one for Canadian temperatures -30 (The Mitsubishsi). The efficiency (COP) drops to 1:1 at some point when it's cold enough so taking a face value Brico judgment is risky.

I have not laid claim or suggested guessing, again it is what you think I said.  The units have fans inside which blow the heat around so your 5kw of heat (@ COP 1:1 in -10 deg) is circulating around the room really nicely and makes you feel nice a warm whereas a 5kw bar fire or radiator would warm up only a small area around the heat source although consuming the same 5kw you would not feel anywhere near as warm.

Very sorry JohnRoss, but if you are going to spend any money on a system I am sure you would want that to deliver.

[/quote]

It's OK I was not thinking you were talking about mine in particular just these systems in general.

What you said intrigued me and I found just doing a quick search this PDF document which I found quite interesting although I have not the time at present to read it fully. The information in it is gathered from many independent sources. I just wanted to get a better technical overview as I am happy to admit I am no expert but have just passed on my personal experiences with which I am more than happy. I would however add that if I were renovating from a shell or building from scratch I would go for a ground source pump which is much better but the cost of installing it in to an existing house is far to expensive. Actually if I built where I currently live I would use water from the river as even in winter it never drops below 8 deg, a friend of mine uses his well which is no longer used as a water supply.

Anyway here is the link.

http://www.ebpg.bam.de/de/ebpg_medien/tren10/010_studyf_09-03_airco_part4.pdf

Now not having a go at anyone but it seems this 1:1 might not possibly be correct, I draw your, and anyone else's attention, to page 51 that shows on average at -10, as that was a figure mentioned, that the COP figure could be between 1.8 to 2.0 and a little lower for -12. If I have misinterpreted the numbers please don't have a go just try and explain my error in simple terms.

Other than that I agree with what you said and have said it myself when discussed before, it is a different type of heat and it gets 'spread' around more evenly we find and with variable pump speed it all adds to making a more efficient heating system.

I am afraid I can't add to the debate about the fire and chimney other than it is important to use dry wood and that you do seem to develop a sense of dryness by weight and age just by its weight. I store mine covered (just the top) for between 2 and 3 years before use and it weighs a lot less than it did when delivered.

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I have been reading this post with interest, because our next neighbour in France has a heat source system, the source is their well. Unfortunately our neighbour who was a very clever engineer passed away and it has fallen to me voluntarily I might add when we are in France, to try to help the old lady next door as this system has been a bit erratic  indeed quite problematic. We called several " heating engineers" for servicing and advice and mostly to a man, they shrugged their shoulders French fashion, and flatly refused to have anything to do with it. I change the filter every two weeks but the other month the system shut down big time, we did eventually manage to find a guy; who came and spent two days giving the system a thorough overhaul, he was kind enough to show me how to read the controls and error messages and it turned out the big problem was that another filter on the pump that brings in the well water was blocked, he showed me how to clean that out. Now touch wood  every thing seems OK. So all I can add is; unless I had the complete ability to care for it; or had 100% reliable back up,  these systems are so complex I wouldn't touch them with a barge pole.

                                    Now a question to Théière about moisture content of wood, we have a large Jotul wood burner and we are delighted with it and it's performance; and yes I do have a moisture metre and I do use it, but after green wood has seasoned, if it gets damp through rain water would that cause problems in the chimney as does green wood, or are you just losing energy drying out the damp log. Cheers

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Nick, the person I know who has this has a 'closed' system i.e. the water that goes round and round is not actually the well water and I believe it contains a chemical as well, an inhibitor perhaps. It might not be such a big deal to change that bit of the system which would need a lot less looking after, just a thought but as I said I don't understand the technicalities of exactly how it works other than what he has told me.
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[quote user="Quillan"]Now not having a go at anyone but it seems this 1:1 might not possibly be correct, I draw your, and anyone else's attention, to page 51 that shows on average at -10, as that was a figure mentioned, that the COP figure could be between 1.8 to 2.0 and a little lower for -12. If I have misinterpreted the numbers please don't have a go just try and explain my error in simple terms.[/quote]

Q, it was more a sense of getting the concept across that with colder outside air the COP will fall dramatically from 3:1 or better.  The actual COP depends on many things not least the design and it's ability to cope with colder weather.  Even the best units will drop to a COP of 1:1 when it's cold enough and the heat needs increasing. The further apart those numbers are the less COP you receive.  It's ok in a lab to simulate but that's not real world and in a cold limestone house you may well need to set the heat warmer than their stated 21 deg and with temperatures dropping to around -17 round our way the other year I would much rather over spec and have heat in reserve than under spec and be cold even if it is only for 2 weeks a year.

 

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[quote user="NickP"]

Now a question to Théière about moisture content of wood, we have a large Jotul wood burner and we are delighted with it and it's performance; and yes I do have a moisture metre and I do use it, but after green wood has seasoned, if it gets damp through rain water would that cause problems in the chimney as does green wood, or are you just losing energy drying out the damp log. Cheers

[/quote]

Nick, The Jotuls are good, one of my favorites.  If the previously dry logs get damp they are just as before, damp and therefore will produce water vapour when burnt so the heat output will be less and the tar deposits more.

 

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