[Sarah1984]

Hi,

I will start to look for a woodstove(20-24kW) to heat my house. Together with this woodstove, I will have a storage tank 1500/2000L. For the moment, I don't know much about woodstoves. I don't want to discuss the kW and the storage tank, nor the use of pellets since I have wood from myself.

I try to find some information on this forum, but since my knowledge of slovenian language isn't enough, I start up a topic.

This is what I want:
- burning chamber for the wood must be minimum 50cm
- easy the clean
- mechanical system, not to much elektronica
- if possible an Slovenian stove
- overheat protection
- good quality

now these are my questions:
- For what price can I find a good quality stove?
- Which Slovenian brands need I to look for?
- Can you advise me a type of stove which would be good for my situation?

With this information, I hope to be prepared to ask questions in the woodstove shop.

regards :wink:

[javr]

For the moment, I don't know much about woodstoves

neither do I, but with those questions, I'd visit my neighbours (from near and far), check what stoves they're using, write down all the Q&A, pluses and minuses, and so on. BTW, my feeling is people usually don't like someone taking photos of what they have installed in their homes, so pen&paper should do just fine.

[Homer]

Bi pa lahko kdo od lastnikov podobnih peči lahko navedel vsaj model in tip (tudi v slovenščini, če ne obvlada angleščino)

[JozkoPetarda]

I think it will be very hard to find Slovenian made "classic" woodstove (boiler) without any electronics that has 50cm deep burning chamber. Those bigger burning chambers are usually present on higher end "gasifying" boiler, that are regulated by electronics.

There are some good boilers available, but everyone has its own drawbacks.

I would choose gasifying boiler, because of easier cleaning, easier operation, better efficiency, 50cm logs. And almost all gassifying boilers have bigger burning chamber, some even over 150l, that helps for less frequent visits to the boiler room. But there will be some electronics involved...

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<!-- m --><a class="postlink" href="http://www.wvterm.si/wp-content/uploads/stadlertr.pdf">http://www.wvterm.si/wp-content/uploads/stadlertr.pdf</a><!-- m -->

If you insist on not having any electronics then take a look for a boiler with "side burning" chamber. Those are probably the best choice in terms of efficiency and ease of use. Also prices of this boilers are almost a half lower than gasifying.
But there are none available (as far as I know) that have 50cm deep burning chamber.

Here are two exaples of "side burning" boilers:
<!-- m --><a class="postlink" href="http://www.wvterm.si/wp-content/uploads/stadlerhs.pdf">http://www.wvterm.si/wp-content/uploads/stadlerhs.pdf</a><!-- m -->
<!-- m --><a class="postlink" href="http://www.wvterm.si/wp-content/uploads/stadlercentral28.pdf">http://www.wvterm.si/wp-content/uploads ... tral28.pdf</a><!-- m -->

There are other producers of boilers not just WVTerm, but I'm not very familiar with their products.

[giovanotti]

Dear Sarah,
for efficient and clean woodburning, there are some fulfilled conditions needed before start:
a. You must have dry wood available. Normally, old farmer's logic says, that wood dries in nature for 2 years, to achieve approx 20% of humidity (wood burning humidity). Prepare wood in time.
b. To achieve efficient (smoke less, minimum ash) burning, besides dry wood, you need heat and oxygen. Efficient primary and secondary combustion (<!-- m --><a class="postlink" href="http://en.wikipedia.org/wiki/Combustion">http://en.wikipedia.org/wiki/Combustion</a><!-- m -->) needs correct ammount of oxygen (which is normally controlled by some electronics nowadays) and combustion chamber, where high temperatures can be developed. Heat in the combustion chamber can be achieved by: insulated, non cooled chamber (construction) and by providing that cold return water (example 30 - 40°C) from radiators does not hit stove directly, but has to be mixed with outgoing hot water to achieve minimum 60°C. Also control of return water to the stove is nowadays (in most cases) controlled by electronics, specially if connected with heat storage tank (1500-2000l).
To avoid electronic control, whole system would require profound knowledge and carefull dimensioning and choice of stove+ chimney (appropriate draft could cause supply of combustion needed oxygen) and thermosyphonic placement of system components (height difference needed). Majority of us do not have these possibilities or apropriate knowledge. Therefore, we use electronics (regulators, blowers...) or have combustion, which is not perfect (consequences: high fuel consumption, smoke pollutes air, ash and creosotes choke stove chimney which needs more cleaning and maintenance).
You did not tell, what is the comfort level, you are used to or you want to achieve. Unfortunately, as everywhere else, higher comfort (less work for loading the stove, less cleaning, better regulation of temperature) equals in more funds needed for project.
How many times a day you afford (timewise) to load a stove?

[Sarah1984]

For the moment, I don't know much about woodstoves

neither do I, but with those questions, I'd visit my neighbours (from near and far), check what stoves they're using, write down all the Q&A, pluses and minuses, and so on. BTW, my feeling is people usually don't like someone taking photos of what they have installed in their homes, so pen&paper should do just fine.

ok, I will do that for sure! I will buy the stove next year, so I got time enough for this.

Bi pa lahko kdo od lastnikov podobnih peči lahko navedel vsaj model in tip (tudi v slovenščini, če ne obvlada angleščino)

:wink:

To Jozko and giovanotti: This is exactly the kind of information what I need when going to the shop. Maybe I should't be to scared about some electronics.

About the comfort level, a burning chamber 50cm would already make a big difference. I have no idea how many times I should fill the stove when heating the stove once a day. I do not heat the house very much. Is one time enough?(not first day off course with cold buffertank :wink: )

edit: Which price category should I look for if I want good quality. And what about best quality?

[giovanotti]

If you set 50cm log as limit (normally, log length is divided to 1m and then further to 50, 33 or 20cm), you have to look for gasifying boiler.

My rough estimation is, that you might need minimum 5k€ for hardware (+ installation work) to start. You can end easily at 10k€+.

[JozkoPetarda]

Maybe I should't be to scared about some electronics.

I think there is more to gain than loose with electronics... but with electronics comes the higher price and of course in times like last few days in Slovenia, there could be some problems with heating when you have electricity black out

. I have no idea how many times I should fill the stove when heating the stove once a day. I do not heat the house very much. Is one time enough?(not first day off course with cold buffertank :wink: )

What source of energy do you use at the moment for heating? What is your current (annual) fuel consumption? This might help to get an idea how often would you have to go to the boiler room.
But the main parameter here is the size of the burning chamber. This can vary from as low as 50 liters up to 170 liters in high-end boilers.
You can't expect that 50 liters is enough for a day (except if you have small or very good insulated house), but 170 liters could easily do it.

From my experience, we have poor-average insulated house, a "high-end" boiler with 150l burning chamber and 2000l buffer tank. We manage to keep the house warm by firing the boiler once a day when outside temperatures are around zero. Usually the boiler runs for 6 hours and in this time the buffer tank is heated up from 35-80°C. This then keeps the house warm until the next day. Inside temperature is 22°C.
If it is colder we have to add a few logs after the first round burns down, if it is warmer (5-10°C) then we only fire the boiler once every two days.

Prices of basic boilers are around 1500€ (no electronics, and lower efficiency), if you choose a gassifying boiler with some basic electronics the prices rise to 2500-4000€. And high end boiler are 4000-7000€ and up.
For 2000l buffer and installation you must add at least 2000-2500€. This also depends on how complicated is you system (how many heating circuits, heating of sanitary water...).

[Sarah1984]

If you set 50cm log as limit (normally, log length is divided to 1m and then further to 50, 33 or 20cm), you have to look for gasifying boiler.

I will do that! What is the Slovenian word for this kind of boiler?

I think there is more to gain than loose with electronics... but with electronics comes the higher price and of course in times like last few days in Slovenia, there could be some problems with heating when you have electricity black out

You got a point! But this will not be a reason not to go for a gassifying boiler.

What source of energy do you use at the moment for heating? What is your current (annual) fuel consumption? This might help to get an idea how often would you have to go to the boiler room.

For the moment I have no central heating, just a woodstove in my living room. Heat loss calculation has been done and a stove 18/24kW is necessary.

From my experience, we have poor-average insulated house, a "high-end" boiler with 150l burning chamber and 2000l buffer tank. We manage to keep the house warm by firing the boiler once a day when outside temperatures are around zero. Usually the boiler runs for 6 hours and in this time the buffer tank is heated up from 35-80°C. This then keeps the house warm until the next day. Inside temperature is 22°C.
If it is colder we have to add a few logs after the first round burns down, if it is warmer (5-10°C) then we only fire the boiler once every two days.

I will be happy with a similar situation. Are you having a WVterm boiler? I went through there catalogue(english!) and they will be a candidate for sure. I've found already 20 topics on the forum with the company's name in the title, so I will have some time to do some translation, to much snow to do anything outside :wink:.

Any other Slovenian brands like WVterm with gassifying boilers?

[CimaBella]

Slovenian word is uplinjak or uplinjevalni kotel na polena/drva.

Slovenian brands that I know of are Waltis (but I would not choose it again, though they have very nice service guys, and one of them is quite good looking :roll: ) and Biodom. Have you looked what gassifying boilers are on Eko sklad list this year? You''ll also have to look for buffer tank - it enables that you fire the boiler once daily, IF its big enough, so you additionally have to know
1. the size of buffer tank (not as easy calculation as one might think, but at least 55 l/kW)
2. where to put it
3. how to get it there

Now, the guys know much more than I do, so better listen to them (but I would say Jožko is one of my favorites if others would not feel ofended :wink: )

[JozkoPetarda]

What is the Slovenian word for this kind of boiler?

The Slovenian word is "uplinjevalni kotel".

Yes we own a WVTerm bolier TR25.
I think their products are high quality, but a bit "rough" on the edges, if you compare them to the best boilers on the market. But nothing critical, mainly the electronics do not offer such expandability as other high end boilers (no option for the boiler to regulate the heating circuits). But looking form the mechanical point of view they are built up to the highest standards. And they are a bit cheaper than their European counterparts.

There are a few other Slovenian brands that make gasifying boilers (Waltis, Biodom), but I don't know their products that good.
And there are many other gassifying boilers available on the market that are not made in Slovenia.
Like Attack, Atmos, Vigas (those are are priced a bit lower, since they are not that sophisticated), and Herz, KWB, Froeling, ETA, Buderus ... (priced at 5000€ and over, very high end stuff)

Now you must decide how much you are willing to spend for the boiler to see which ones are in the game.

For the moment I have no central heating, just a woodstove in my living room. Heat loss calculation has been done and a stove 18/24kW is necessary.

I will be happy with a similar situation.

It is hard to judge the consumption from that data, also the calculated power of the boiler does not tell much.

I can tell you that our house is quite big around 250m^2, but only 170m^2 is used as a living space and heated. It is insulated with 8cm thick styrofoam on the facade, and 15-20cm thick wool on the roof. Windows are 25+ years old and far from today standards.

At the moment we consume around 12-13 m^3 of wood logs per year with this WVTerm boiler.
Before buying this boiler we used heating oil and older type of "side burning" boiler. Per season we used around 2700 liters of heating oil (when only oil was used), or 22m^2 of wood logs (when we only used old boiler without the buffer tank).
Maybe this will give you a better idea of what to expect.

[Sarah1984]

ok!

thanks for all given information, I can start doing some homework :wink:

S

[gape]

This forum, would be a very nice place, if every theme, would be answered in such fine manner. :wink:

[JozkoPetarda]

This is a very nice place, as long as you manage to keep the "heat pump guys" and their "Holy war" out of the discussion...

[Sarah1984]

Hello,

I was at the fair in Celje this year and I had a good opportunity to have a closer look at the wood gassifiers.
For the moment, I'm trying to choose between KWB and WVTerm Stadler TR. I suppose both of them will do the job.
So, If you had to choose beween these 2, which one would it be?