Every system of pipe,fittings,components should act as a ‘resistance’ in the same way, and its a square law, so dropping power had less affect on flow than expected, But it should be noticeable.
Is this your flowrate? (I added a x16.66 to get it to lit/min)
So, drilling into a recent graph, I can see a section at 5kW and dt5. this should equate to 14lit/min, but you are showing only 9lit/min… There are no sections with a dt greater than 5… what an I missing??
Still showing a very low and regularly-low Carnot COP, as might be expected with such a low flowrate.
dt does go considerablt more that 5, but dt kW and flowrate dont seem to add up. interesting to see expected heat oupput if Carnot cop wer 49%, its nearly achieving this at one point
With the pump on max, I’m getting around 1.3m3/h.
It didn’t seem to drop much when on the middle setting so I went to the lowest one yesterday around noon and that was around 0.5m3/h.
House definitely didn’t warm correctly this morning so I’ve put it back on the middle setting and changed the mode to constant pressure and that’s giving me just shy of 1m3/h so I’ll leave it at that for now. Sunny here again so HP off for a few hours I expect.
I bow to John because he is far more knowledgeable than me and I follow his reasoning to learn, my thoughts as an installer is most of your circulation, flow rate issues are based around your buffer because I think this is where all of the resistance is happening. So as per my pic ( earlier posts) so not only do you have re circ going on but I think your zone pump return is pushing against your heat pump flow due to the distances between the tappings. So when you reduced to the lowest setting your zone pump is just pulling mixed water cooler water from that side of the buffer.
It’s easy to make comments and suggestions but I am aware that there is a cost to whatever you do with no guarantee that it will work.
If it were mine I would be looking to cap off my buffer first and re pipe the system without the buffer, take out the zone pump and have one circuit. Have the system then as an open system because only then will you have a true representation of flow rates and dT. Like I said I’m no expert but it’s a logical way for little cost.
I’m going to speak to John next week.
I’m currently thinking that converting the layout from a four to three pipe buffer might be the solution, especially as the current layout makes that fairly easy plumbing wise other than having to drain the buffer.