A buffer tank on a pellet boiler

[lv13r]

hello I would like to know if a buffer tank is very useful on a pellet boiler because (if I understood everything correctly the balloon is a kind of battery that charges and that we use when the boiler is stopped, example boiler has log (empty) (or for solar) the balloon takes over, but
the pellet boiler it is permanently supplied, a bit like fuel oil or gas, it starts as soon as the request is made then goes to standby (or maintains) so what interest the buffer tank ??? I have read the posts concerning LV on the e forum
but I don't really see the usefulness of the buffer in the case of writing above
please
lv13R

[dirk pitt]

you are absolutely right, the buffer tank is a palliative to the problems of regulations and intermitences of certain heat sources.
the pellet boiler is automatic and modulating therefore, if it is dimensioned correctly, it permanently supplies exactly the quantity of energy sufficient to compensate for the thermal demand of the heating circuit.
in this case the balloon is useless.
it must be seen that the ball is not a "plus" in itself, it has thermal losses and its presence is only justified if it provides a solution compared to a worse situation at the start.

[Christophe]

In addition in all cases you have the DHW tank which acts as a buffer (reduced but still buffer)

[lv13r]

thank you dirk pitt and christophe
so ok i understood everything
I have to modify my fuel system to install a multi-fuel boiler (varnish 25kw) + 300L hot water tank
I was thinking of putting the fuel boiler in parallel with the varnish
but when I look at the different plans on the net I always find the two boilers in series ???
WHY
what is the point of passing calories in a boiler that does not work ???
LV13R

[Christophe]

Uh you haven't looked at the diagrams on econo then

What patterns? Put them here if you find them ...

[dirk pitt]

In addition in all cases you have the DHW tank which acts as a buffer (reduced but still buffer)

uh .... i don't know what you mean, christophe,
the hot water from the DHW tank is never returned to the heating circuit so there is no "buffer" effect
the DHW tank accumulates heat but never releases it (except in the shower water of course )
possibly, the only beneficial effect that I see him would be to absorb a surplus of available heat when the demand for heating is low to avoid that it stops too often.

[Christophe]

Well a pad is a pad, that is to say that it reduces the ON / OFF of the heater and the installed power ... In addition with a wood boiler it prevents overheating even a balloon ECS.

It is in this sense that I said this!

A single shower can take 60kW instantaneously according to your flow / T °! It's huge ... it's been a long time since we understood the interest of dabbing in a DHW tank ...

[loop]

Hello

There may be an advantage in placing the wood boiler in series before the oil boiler returns.
When the wood boiler (log or pellets) is running, the water entering the oil boiler is already hot, preventing the latter's burner from starting.
When the wood boiler stops, the temperature of the circulating water drops, and the fuel oil boiler starts up "hot" as soon as the calorstat setpoint temperature is reached.
A small regulation and a motorized 3-way valve should then allow to bypass the wooden part, as long as the oil burner is operating.

I can make a sketch if you wish

A+

[Christophe]

Well, I would see the opposite rather: bypass (at least in part) the oil boiler with 1 motorized 3-way valve and a simple all-or-nothing regulation (all = € 200 max) ... Because permanently heat the body of heating the oil boiler is a pure waste ...

[lv13r]

thanks for the answers
christophe ben if i looked at your diagram on your instal but i find it difficult to grasp everything because between the pc the buffer tank the solar plus the multitude of valve and accelerator .....
more c is far from what I have at home (a fuel boiler an accelerator a dozen short radiator c is basic basic home even the water heater is electric
a question about this is what can i use the balon of
300 L that will be mounted next to the varnish to heat it by solar panels in the summer (winter water from the tank heated by the varnish and the summer by solar panels)
if possible put a small diagram (if it is feasible),
This is why I am looking for diagrams for a good compromise, knowing that everyone tells me that we cannot operate a multi-fuel boiler below 80 °.
in boiler water temperature (risk of condensation in the duct and in the boiler (pink point) while my fuel and regulates at 60 °
please
lv13R