Some very useful things to think about above. I’m learning a lot.
In other news, the overnight hot water cycle is now visible in the graph. There must be some cacheing going on - I just had to stop and start the docker container.
Emoncms - app view
Basically there’s a rise in temp of 200L of water from 37.8 to 45 using 1.137kWh. My kWh accumulator for the 30 minute period to 05:00 showed 1.106, so very similar (about 8p, which is acceptable in cost terms, but does it tell you anything about the pump performance in general?).
And then there’s the buffer. I currently have temperature sensors on all 4 pipes of the buffer and it’s interesting. I will read up on that link about thermal paste etc, but for now, for example:
pump → 37.1 → buffer → 35.3 → underfloor
pump ← 33.6 ← buffer ← 28.6 ← underfloor
I have read somewhere about 3 vs 4 port buffers - effectively biasing the buffer to only the input or the output. Is this something you are familiar with? And then there’s the question of whether the buffer is strictly necessary. I’m told it’s functioning to both add volume and to give hydraulic separation to the two pumps. I can understand not wanting two pumps to fight each other, but I don’t know about the “adding volume” that’s often mentioned. I’d be very surprised if the water pump in the LG unit could do the entire job on its own with the help of a second pump.
As for the zones, there is a Polypipe manifold and controller upstairs and another downstairs. Each room has a thermostat and that controls one or more solenoid valves on the manifold - on or off. In addition there are flow controls on each zone but they’re fairly crude and hard to adjust. The pump on the consumption side of the buffer is controlled by either of the manifold controllers having 1 or more zone valves open.
I could run the system wide open, but I suspect it would be a nightmare to balance the temperatures in different rooms. And I certainly want the bedrooms cooler than the living spaces downstairs.
Are there any examples of weather compensation curves that you know of? I’d like to see what they look like. I suspect wouldn’t take me more than maybe an hour to implement one to experiment with. I realise that the LG has a built in “AI” mode (sarcastic quotes again), but it’s a black box and I don’t like those, especially when they just ramp the flow temperature to 45. Even when you say “run it like a gas boiler”, 45 seems a stretch?
