what power for a wood-log boiler?

[CHAMODON]

I would like to install a heating system including a woodburning log-burner boiler, a 1000 liter buffer tank to supply two heated floors with a total area of ​​135 m², a 300 mixed electric boiler-boiler liters.
My heating need on our future house is 10 kW.
I made plans following bioclimatic eco-building rules. In particular, most of the openings (bay windows) are oriented south-east. The house will be heated in part by passive solar.
What power of wood-log boiler should I install?
Thanks for your help
Bruno

[pipo]

Why a boiler and a heated floor if your house is really well insulated, no need for all this, a good stove 2000 euros and everything is good.

I renovated an old house in 1967 never finished at the time, really a "ruin" I kept the walls and the roof. I have a great need for heating compared to yours so underfloor heating with 25 kw wood boiler and 2 * 800 liter tanks. Autonomy when it froze last week 24 hours for 85 m2 of heated floor on the ground floor upstairs no heating for the moment.

[Did67]

One or two principles:

1) Design your system so that you can flambé your logs "thoroughly". Otherwise, the combustion will be "smothered" by the regulation of the boiler and it becomes an ecological disaster. Far from being "green", wood heating then becomes a real pollution (apart from the fact that it is CO² neutral).

2) So calculate your buffer so that it meets the maximum needs (at the coldest) for the duration between two outbreaks. Let me explain: will you want to force yourself to light the fire once a day? two times ??

Your tampon will have to provide the calories you need to heat a day or half a day.

3) This determined, the capacity of the furnace of your boiler must correspond to the storage capacity of your buffer. In other words if you light, you will not be able to stop the fire. So all the calories produced will have to "fit" in your buffer.

This is what is decisive.

The power, strictly speaking, will have to be especially related to the capacity of your exchangers / circulators ... (it is a question of evacuating the calories produced in the home to avoid that the security is triggered). Your power will not be related to the needs of your house, since you store your energy in a buffer ...

Here is the principle. After, it is necessary and it is enough to calculate !!!

[CHAMODON]

Why a boiler and a heated floor if your house is really well insulated, no need for all this, a good stove 2000 euros and everything is good.

I renovated an old house in 1967 never finished at the time, really a "ruin" I kept the walls and the roof. I have a great need for heating compared to yours so underfloor heating with 25 kw wood boiler and 2 * 800 liter tanks. Autonomy when it froze last week 24 hours for 85 m2 of heated floor on the ground floor upstairs no heating for the moment.

It's true you're right about the fact that a stove might be enough. However, I wish to have the comfort of the heated floor.
Hence the investment ...

[CHAMODON]

One or two principles:

1) Design your system so that you can flambé your logs "thoroughly". Otherwise, the combustion will be "smothered" by the regulation of the boiler and it becomes an ecological disaster. Far from being "green", wood heating then becomes a real pollution (apart from the fact that it is CO² neutral).

2) So calculate your buffer so that it meets the maximum needs (at the coldest) for the duration between two outbreaks. Let me explain: will you want to force yourself to light the fire once a day? two times ??

Your tampon will have to provide the calories you need to heat a day or half a day.

3) This determined, the capacity of the furnace of your boiler must correspond to the storage capacity of your buffer. In other words if you light, you will not be able to stop the fire. So all the calories produced will have to "fit" in your buffer.

This is what is decisive.

The power, strictly speaking, will have to be especially related to the capacity of your exchangers / circulators ... (it is a question of evacuating the calories produced in the home to avoid that the security is triggered). Your power will not be related to the needs of your house, since you store your energy in a buffer ...

Here is the principle. After, it is necessary and it is enough to calculate !!!

Thank you for this relevant info, so I will calculate ...
I also thank you for taking the time to answer so completely.

[pipo]

What I have, vigas 25 kw, rustic but it turns, 20 kg of wood for 800 liters (by default, 1000 by excess) which pass in 4 hours of 26 ° to 76 °, autonomy with -2 ° the night, 24 hours for 130 living square meters and 180 m2 floor - lots of crawling not much insulation

(2 buffer * 800 liters including one with solar heat exchanger for later, I have too much work with the rest right now)

For 135 m2 floor heating I would aim a power 40 kw and at least 3000 liters of buffer, it is not necessarily huge and it provides good security, can store a whole load of wood without risking overheating.

Price on ebay (I bought at the same) 5900 euros ttc without the delivery (count 450 euros delivery, it is the international I had to lodge even if I live at 15 bounds of the border!)

Good luck

PS An important thing, the smoke duct, minimum 12 m in 180 mm to have the draw and to mount a moderator of draw to not have too much draw when the duct rises in temperature. It's not a French habit to set print moderators, but it's useful!

[CHAMODON]

What I have, vigas 25 kw, rustic but it turns, 20 kg of wood for 800 liters (by default, 1000 by excess) which pass in 4 hours of 26 ° to 76 °, autonomy with -2 ° the night, 24 hours for 130 living square meters and 180 m2 floor - lots of crawling not much insulation

(2 buffer * 800 liters including one with solar heat exchanger for later, I have too much work with the rest right now)

For 135 m2 floor heating I would aim a power 40 kw and at least 3000 liters of buffer, it is not necessarily huge and it provides good security, can store a whole load of wood without risking overheating.

Price on ebay (I bought at the same) 5900 euros ttc without the delivery (count 450 euros delivery, it is the international I had to lodge even if I live at 15 bounds of the border!)

Good luck

PS An important thing, the smoke duct, minimum 12 m in 180 mm to have the draw and to mount a moderator of draw to not have too much draw when the duct rises in temperature. It's not a French habit to set print moderators, but it's useful!

thank you for this information, especially the moderator of draw that I do not know.