Pipe diameter buffer tank france solo innova 30kW

[boomcox]

Hello,

I'm going to install an HS france solo innova 30kW boiler with a buffer tank that will do the DHW, they will be 5/6 meters apart.
The inlet/outlet diameters (boiler and buffer tank) are 1"1/4, i.e. a 42mm pipe.
I have some 40mm fittings, I can do the installation in 40mm or I have to stay in 42mm. Otherwise, it does not matter, I will sell my fittings.

If you have an idea?

Thanks, have a good day

[Christophe]

Same answer as in the other subject: the bigger the better from a hydraulic point of view...but it's more expensive and more heat loss...

With 1 1/4 you can even start making thermosiphon if the heights allow it.. that is to say an assembly without circulator...

[boomcox]

Thank you for this explanation
The balloon is at the same level as the boiler so it's dead for the thermosiphon

[Philippe Schutt]

to pass 30kw over 12m, an inside diameter of 30 is enough. Afterwards, depending on the type of pipe, you take the diameter just above. Thus in copper of the 35, in black iron of the 42.
You have coins in 40, so I assume copper? it's largely enough.

[boomcox]

In fact the orifices of the boiler and ball are provided for iron,´.
Another question that came to me in this discussion is the slope of the pipes. On the heating outlet that we see in the basement, it's flat, I'm not going to do it again but for the balloon, wouldn't it work better with a little slope?
Excuse me with questions that seem ridiculous, for practice it's fine but then the theory.

Thank you all for your interest in my messages.

[Christophe]

The slope only counts in thermosiphon…with a circulator you want to do whatever you want…

[Philippe Schutt]

In fact the orifices of the boiler and ball are provided for iron,´.

ok, you're talking about 40 fittings, whereas it's 42,3 in principle the 1"1/4. So what is the tube? what is its assembly method?
And in 1"1/4 threaded outlets the 40 will have a crazy game.
So in any case, you will need parts in 33/42 (1"1/4) male towards your 40

[boomcox]

Philippe, I'm going to stay in copper, it's probably more expensive but so much simpler.

Good weekend

Nicolas