Ok some more info on the new setup which may be of interest- specifically the comfort offset automation which adjusts the flow temperature if the IAT is outside of the comfort parameters, and an interesting observation over the last couple of days now that it is a bit warmer.

The above shows the comfort offset history for the month, so it will adjust the LWT by 2 degrees C either way, depending if the IAT is undershooting or overshooting. It hasn't actually run that much, which is what I was hoping/expecting. On 13th March it must have been windy and needed a boost. On the other days where it has offset -2, this will be down to solar gain.

What the adjustment effectively does when warmer, is that it turns the ashp off- so if the set LWT is then below 29 degrees C which is the lowest temp that it will run. This actually works perfectly. As per this graph (red arrow where the comfort offset has pushed the set LWT below 29)

I think now I can confidently say this is our ideal setup in terms of control strategy, and I can probably leave as it is.

@benson — well done! My auto-adapt does pretty much the same thing, infrequent but useful adjustments. The advantage of using our own code is that we can tweak it to achieve control that works for our particular setup.

Posted by: @cathoderay

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My auto-adapt does pretty much the same thing, infrequent but useful adjustments.

I presumed when Gemini was writing the automation code for me, that it was data farming from your forum posts about your set up 😆 

It does work well- thanks for all of your help, and everyone else who has advised along the way.

Posted by: @benson

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I presumed when Gemini was writing the automation code for me, that it was data farming from your forum posts about your set up

Spooky! I think you already know I don't use AI much, but if I did, and found myself asking it a question and finding the answer seemed curiously familiar, I might end up thinking I need to start taking the tablets again!

Posted by: @benson

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It does work well- thanks for all of your help

A pleasure, and thank you for documenting what you have done here. I am sure the other who have contributed have also been glad to do so. 

@cathoderay For what is worth, it was recently pointed out to me, in a Greek heat pump forum, that certain high-end manufacturers, like Hitachi or Daikin, do indeed offer an IAT compensation mode.

So I had a look at a Hitachi Yutaki ASHP manual and indeed there is an option of room temperature compensation, which I quote:

"Room Temperature Compensation

If room compensation is enabled, the calculated OTC supply set-point is adjusted based on the difference between room temperature and room set-point in order to reduce the room error. The amount of room influence can be adjusted by the room temperature compensation factor setting (can be adjusted, default 2).

Example

Compensation factor = 2,

SR1 (room set-point) = 20,

TR1 (room temperature) = 23

=> S1 (supply set-point) reduced by 2 * (23 – 20) = 6C "

Even though this is a rather crude approach, I think it does show the future, which is very well predicted by your reported actions here.

@tasos — despite what Gemini may have been up to, I don't claim any originality for what I did, which was simply to implement a basic feedback loop! I had the idea of such a DIY implementation after hearing about Ecodan's auto adapt mode, and thinking setting up something similar in python should be very straight forward (and it turns out it is). I haven't done the same thing for forecast weather, because a forecast is only a forecast, but I am sure it could be done without too much extra effort ('if forecast windchill > X then increase LWT by 1°' etc) by anyone who wanted to add it.