Amount of wood needed to log stove

[Stephen King]

Hello everyone, I have a mini project to biomass, to see what it would take for the average family to heat only from biomass.

I sized installation of 13kW (Cerval Wood stove for logs of 55cm).

I will take beech, whose sterile power is 2000kWh / stere.

My problem is how many cubic meters (or logs if possible) I will need if I want to warm 5 6 hours a day for months or 900 hours of heating.

I admit I am lost cubic meters compared to the units, the heating power etc.

Thank you

[Forhorse]

Ben it's simple math.
13Kw x = 900 hours 11700kWh
2000 kWh per cubic meter so 11700 / 2000 5.85 cubic meter =

Now apart from that I know nothing, no idea if the results without cohérant or not.

[Christophe]

If you have dimensioned for 13kW crete you must have an idea of ​​the losses of housing no?

And so useful kWh needed annually heating not? How did you size the stove?

Otherwise you have to make a heat balance to assess needs (I speak not of a DPE that are a face but a real small thermal study) ... or from an existing consumption (heating oil = 1L 10kWh, 1 3 m10 gas = kWh) ...

[Ahmed]

As a first approximation, it takes 13 to 15 cubic meters of hardwood / year to heat an average "electrical insulation (sic!)" Type pavilion.
This for continuous heating, hot water out.

I understand you're a little lost in the units of measurement: it must pass the calorific / kg, the average weight per cubic meter, the latter representing a rather approximate apparent volume!

[Ahmed]

I have just read the answers of Forhorse et Christophe.
The calculation of the first is exact, except that the initial indication provided is erroneous: it is a stere of beech which gives about 2000 kw (a beech stere = 0,60 M3).
Of course this does not mean he will do good in this house! For this, we must know, as the saying Christophe, What are the losses or current consumption.

[Christophe]

Ben it's simple math.
13Kw x = 900 hours 11700kWh
2000 kWh per cubic meter so 11700 / 2000 5.85 cubic meter =

Now apart from that I know nothing, no idea if the results without cohérant or not.

Ah, I would not have thought this method but the result seems to me low for a 6 month heating season ... finally all depends on the needs ...

I believe (we lack information on the question) that the power of a stove is the nominal (maximum) power, you only expect it a few hours in a day, and by loading the stove well ... reality and on average if we are at 50% of the nominal power over 5 hours it is "not bad" and therefore we would find less than 3 cubic meters.

A then corrected by the performance of the stove (75% with a quality stove).

Otherwise, I think we can use a stove that 5h per day heating period so that we ca to heat: it is 10 to 12h need he must turn ...

This is why it is important to learn more about the housing where it is installed stove and how was sized the stove!

ps: ah well I think we 2000 kWh per cubic meter (thus counting empty in a pile of wood m1 3) and not m3 ... but with wood that is so variable (nothing that 'humidity).

I have always believed that this painting and assimilated m3 stère but you may be right: https://www.econologie.com/pouvoirs-calo ... bustibles/

[Christophe]

Oh no it's many cubic meters in this table because the density of the beech is to 700 750 kg / m3 2 from these pages:

http://pagesperso-orange.fr/contescourt/ld/hetre.htm
http://fr.wikipedia.org/wiki/H%C3%AAtre_europ%C3%A9en

And we recover the 400-450 kg / cubic meter by applying your coefficient of 0.6: 750 0.6 * = 450 kg / cubic meter.

And so according to the above table so we well 1 beech stère ranging from 1650 1850 in kWh / cubic meter dry beech!

To correct the stove efficiency (75%) is at best 1400 kWh / cubic meter.

Voila, so I think 1400 kWh / cubic meter of dry beech is given to retain the heat balance wood heating.

[Forhorse]

Me too it seems to me weak, but good as I said, I did only the calculations with data provided.
For heat only 5 hours a day must be a great house well insulated, or live in the south of France ...
My parents lived in the mountains, in an isolated "electric heating" pavilion (according to the standards in 1983) and there the fireplace was running 24 hours a day and the wood consumption was more like 24 to 20 cubic meters per year ...

[Stephen King]

In fact, I talked sizing but I took such magnitude that had a 1kW heating power to 10 130 m² m² for so I felt at 13 kW.

Being a mini project, the professor asks us to do "roughly" the estimate of the quantity of wood necessary ".

The method Forhorse which I also thought seems to me too simple fact.

Because as you say, Christophe, the stove does not always running at full capacity so it is difficult to estimate the number of stère necessary even for a fixed number of hours.

Too bad, I'll consider that as soon as you turn on the stove we immediately reach the rated power of the stove, even if it's completely false. It will be an overestimation of the number of necessary cubic meter, but we also we lack information.

Our subject is a bit wobbly, we must do for an average family living in the countryside, but it is too vague, depending on the layout of the house etc, so I just took an order of magnitude.

I'll just change the hours of operation to be a little closer to reality.

Thanks for all.

[Christophe]

In fact, I talked sizing but I took such magnitude that had a 1kW heating power to 10 130 m² m² for so I felt at 13 kW.

Ouch...

Never, never, you never chaufferas 130 m² with a single stove 13kW except very specific case: a large room with air that communicates easily and well positioned in the middle stove ... and again!

This is an ideal case we never meet in renovation ...

Oh, it's a trick to school so a year? So let the concrete heat balance ... because I assume your teacher. do not mention it ...