Problem of autonomy on hydroaccumulation with wood

[bertrume]

Good morning all...

I just installed a 28kw wood boiler a few weeks ago with a 1500l buffer tank. Everything works well, except that the autonomy of my balloon, boiler off is only three to four hours ... I would have hoped to arrive at 10 am.
My house dates from 1975 reinsulated correctly, 9 radiators and an area of ​​about 160m2.
My question is: is this normal autonomy for the volume of the balloon? are there any avenues to explore?
Thank you in advance for your answers.

[Former Oceano]

Hello, more elements are needed, including the temperature of the water in the balloon, location and insulation of the balloon.
For info on Marseille for a house of 100 m² I have a gas boiler of 45KW.
Fortunately it does not work 24 / 24H ...

[loop]

Good evening,

As ex said, there is a lack of data.
The power of the boiler is one thing, but if all the calories go into the instant heating of the house, normal that the balloon does not charge.
To control the correct load by stratification of the tank, it suffices to control the temperature of the tank from top to bottom.
Normally, if the load is correct (without too much mixing), it is necessary:
1500 * 1.16 * 50 = 87 KWh / 28 = 3 hours of heating
I assume here that the boiler only heats the tank from 20 ° C to 70 ° C. It remains to be seen whether hot water can be used in the radiators when the temperature has dropped.

A+

[Former Oceano]

hush looping, you shouldn't say that I was your ex!

[bertrume]

Thank you all .....

For details, my boiler is well sized, it heats my radiators and the surplus heats the balloon to 80 degrees in three hours ... the stratification is done well, I control all this with the thermos, ...... the ladomat can also be cut after heating ... well, on that side, everything works well.
It is the autonomy of more or less four hours which poses a problem to me .... four hours after stopping the boiler of course!
It is true that at the moment it is cold but hey I expected more.
What do you think ..... otherwise a big thank you for your posts regarding heating, I used it to complete my installation.
Thank you for your answers

[bertrume]

For info: the balloon is in a room where it averages eighteen degrees, it is insulated with ten centimeters of insulation, and if it is not used the water does not fall absolutely ... so on the balloon side I think everything is ok ....
Thank you

[Sunflower]

Hello everyone.
Simple question you are talking about autonomy of 4 hours, with a temperature of 80 ° at the start, but what is the temperature after 4 hours?
If the house is well heated at the start, your living room controller should stop the call for hot water once the set temperature has been reached (say 22 °) and only restart the system once the temperature is below the set point and so right now.
This should increase autonomy.
As far as I am concerned, I have never really made any measurements of autonomy. I use the buffer tank when I am not at home or in bed ... so set temperature 18 ° ... in the House.
Here it is.

[bertrume]

Hello ....

After four hours the temperature is between 50 and 55 degrees .... so no longer very usable for my radiators .... I am not in heated floors or in low temperatures.
Here I speak of 4 hours during the day, at night I program and I therefore hold longer. So I'm talking about four hours of heating to maintain 22 degrees in the house ...
Thank you for your answers

[dirk pitt]

well we all have what it takes to do the math.
you start from 80 ° to descend to 50 ° or a delta of 30 ° of 1500L of water.
the energy thus dispensed is therefore:
1500x1.16x30 = approx. 52kWh

if you say that it is exhausted in 4 hours, it is that the heating of your house (under these conditions) requires 52/4 = 13kW of power, which seems to me quite consistent for a house of 160m2 at 22 ° VS

so nothing abnormal: the size of the heat tank if you wanted to have eight hours of equivalent heating should be doubled.

[I Citro]

Super interesting this post.
So if my insulation is correct, with my low temperature radiators I could store 8 hours of heating with less than 3m cubic buffer for my house of 115m² the ceilings are 2.5m.
(I have a wet basement in shuttered concrete).
My new 12 kW boiler is working wonderfully for now but I plan to go further (solar buffer and reversible air conditioning as Maloche with possible thermodynamic back-up of the solar water heater.