@papahuhu I found that as well with homely. It generally seems to 'ignore' set backs. That said it's not like it would be that easy with my current setup to achieve either. I asssumed it just ironed out set backs due to it being detrimental to efficiency.
17 IAT we'd find absolutely baltic though 🤣 . Generally we like it around 21 (with no set backs, and perhaps a bedroom window opened very slightly at night).
A few more observations. Generally over the last few days it's been a case of heating kicking in overnight to keep the house at around 21, and then off during the day as the house will be perfectly warm enough due to warmer OAT + solar gain. I've now got one simple automation for the heating to come on if the hallway temp sensor drops below 20.8, and one to turn off at 21.5. This is only really to mitigate for the fact as above that we don't need anything during day once sun comes out, so when a bit colder I don't really anticipate using these and it will just be on all the time.
Black arrow indicates when temperature has just dipped below 20.8 overnight.
More detailed graph of IAT, red arrow indicating when automation has kicked in. This has then kept the temperature nice and steady overnight up until 0800 when the OAT has increased and solar gain has heated the house. Therefore the WC curve settings seem about right now.
One annoyance- I have realised that any automations that alter the serviceman settings (such as WC curve) turn everything off, just as it would if you access the serviceman settings on the physical control panel. This is such an annoying design feature with the midea!
Now the only time this is going to potentially be a problem is if I have an automation set up to alter the WC curve values to compensate for any overshooting, thus presumably I will need to then set up another automation or building block perhaps(?) to turn everything back on. @cathoderay- have you experienced this at all with your setup and overshooting adjustment you mentioned that you have?
One other observation. COP figures from energy monitoring have definitely taken a dip, following the adjusted WC curve setting with the lower end being 26 rather than 31. Now around 4.3 to 4.4, whereas it was more like 5.0 when set at 31 and more on/off overnight. I presume this is because the 12kW struggles to modulate down this low so whilst it is probably actually cheaper cost wise as it isn't overshooting when running overnight now, it is slightly less efficient in doing so perhaps in terms of kW grid consumption in, versus kW heating out.
I've now got one simple automation for the heating to come on if the hallway temp sensor drops below 20.8, and one to turn off at 21.5.
More detailed graph of IAT, red arrow indicating when automation has kicked in.
One annoyance- I have realised that any automations that alter the serviceman settings (such as WC curve) turn everything off, just as it would if you access the serviceman settings on the physical control panel. This is such an annoying design feature with the midea!
Please excuse my ignorance but what do you mean by "automations" ?
Midea MHCV10WD2N7 R290, 4.8kW peak energy community solar power.
@tasos automations on Home Assistant so if there is a pre defined change to an entity (in this example, if my hallway temperature sensor drops below 20.8) this will then trigger a change in state of another entity. In this case it turns my zone 1 heating on via my heat pump controller.
Incidentally today it has been a fair bit colder during the day at around 11-12 degrees C. I haven't touched anything since last night when my heating kicked in when it dropped to 20.7 just after midnight I think. Since then it climbed steadily to around 21 degrees C and it has been hovering very close to that ever since. Thus, everything seems to be working really well.
My only slight concern as mentioned above is that the COP from energy monitoring seems to have dropped slightly now that I have set the lower target LWT on the warmer end of the curve. It seems to have settled at around 4.4 whereas before with this set at 35 at 15 degrees C OAT it was closer to 5. That said, I guess it is only an estimation anyway. Energy usage has definitely been reasonable.
Now the only time this is going to potentially be a problem is if I have an automation set up to alter the WC curve values to compensate for any overshooting, thus presumably I will need to then set up another automation or building block perhaps(?) to turn everything back on. @cathoderay- have you experienced this at all with your setup and overshooting adjustment you mentioned that you have?
My version of this uses a standalone python script that runs once an hour. Connect via minimal modbus, and then a series of if/then statements eg if IAT is 1 degree too low, then raise WCC by 1 degree at each end. It also logs what it does and generally works just fine. I imagine something similar could be done in HA, and as it already has a connection to the wired controller, no need to use minimal modbus.
Now the only time this is going to potentially be a problem is if I have an automation set up to alter the WC curve values to compensate for any overshooting, thus presumably I will need to then set up another automation or building block perhaps(?) to turn everything back on. @cathoderay- have you experienced this at all with your setup and overshooting adjustment you mentioned that you have?
My version of this uses a standalone python script that runs once an hour. Connect via minimal modbus, and then a series of if/then statements eg if IAT is 1 degree too low, then raise WCC by 1 degree at each end. It also logs what it does and generally works just fine. I imagine something similar could be done in HA, and as it already has a connection to the wired controller, no need to use minimal modbus.
Interesting that you change the values at each end I never thought of that I have only been adjusting the max flow temp at the cold end, do you find that this makes much of a difference?
Kind Regards
Si
——————————————————————————
Grant Aerona3 13kW
13 x 435w + 13x 480w Solar Panels
Sigenergy 10kW Inverter
16kW Sigenstor battery
I think so. It also makes it easier for me to visualise what happens to the 'curve' (quotes because it is a straight line between the end points), eg if both ends go up one degree, then at every point along the curve the LWT has gone up by one degree.
One of the advantages of using a script is that you can set it to do whatever you want it to do. The only two related things to watch out for are (a) setting up a positive feedback loop that will increase your set LWT to 100 degrees and counting, and (b) anything else that could do the same thing.
Midea 14kW (for now...) ASHP heating both building and DHW
@cathoderay thanks. That is similar to what I'm trying to set up via the automations, but need to tweak these to turn the heating and DHW back on if the automations run, as this is definitely turning everything off (as it would if I physically went into the serviceman settings).
That said, I am managing to keep my house very close to 21 just from the set curve with no adjustments. So far, so good (not sure what has caused the missing data for a small period for OAT).
Using the overshoot and undershoot adjustments are a little complicated though as I'd then need to set another automation to reset it back to standard curve settings within certain temperature parameters. For example, I could have one overshoot adjustment to kick in at 21.5 to lower the curve a little. Another at 20.8 to increase slightly. Between 21 and 21.3 to revert back to standard set curve perhaps....
I wonder if all of the above also explains a nuance/fault I had with homely, which was that every so often the DHW wouldn't be reheating during scheduled times and I couldn't work out why. Was homely altering the serviceman settings and then inadvertently turning it off.
On gas we had had 3 zones and three thermostats, we’ve gone to a single zone open loop so it’s not surprising that the heating outputs will be different. On gas we had the thermostats on 12C, so 17C is tropical.
I’ve never understood why people would waste money on excessively heating a house when all they need to do is pop on a jumper and save hundreds of pounds a year. That saved money can be used for something far more useful than being able to sit in a pair Speedo’s!
That is similar to what I'm trying to set up via the automations, but need to tweak these to turn the heating and DHW back on if the automations run, as this is definitely turning everything off (as it would if I physically went into the serviceman settings).
That is interesting, and something you mentioned before, but which i didn't directly address. When my auto-adapt script runs, and changes settings over modbus that would be done via the For Serviceman menu on the wired controller, it doesn't turn things off. I wonder if it is something about the way HA accesses things that makes it 'as if' it was a manual change on the wired controller?
Was homely altering the serviceman settings and then inadvertently turning it off.
Again, very possibly. If HA can do it, and then Homely uses the same approach (amd I right in thinking it uses python as well?), then both would have the same effect.
Midea 14kW (for now...) ASHP heating both building and DHW
@cathoderay yes perhaps. It seems quite an easy fix to immediately turn everything on again if an automation does run, but interesting your setup doesn't do this. Just don't really get why midea designed it this way.
Not sure about homely and if it uses python to be honest.
