It tends to more technical discussions there

As mentioned .. from info in LG user group it does reduce cycling and output. But I don't use it myself as my heat pump seems approx right size.

I dont know if other ashp have similar function?

Then forcing the cycling to effectively a shorter time on period would be a good first tactic. This would work best with high thermal mass, eg. UFH or solid brick house with good insulation. Aligning the on time to cheap electric is an opportunity.

Pretty much I'm coming to that conclusion, TBH it was my hunch when I started this thread but I wanted (and still want) to see if anyone comes up with anything different.  So far not but it's still open to debate.

I agreed with your approach on the other thread and so pulling out the general case is a better way of capturing it.

Then forcing the cycling to effectively a shorter time on period would be a good first tactic. This would work best with high thermal mass, eg. UFH or solid brick house with good insulation. Aligning the on time to cheap electric is an opportunity.

Pretty much I'm coming to that conclusion, TBH it was my hunch when I started this thread but I wanted (and still want) to see if anyone comes up with anything different.  So far not but it's still open to debate.

John Cantor covers this well in this YouTube session https://m.youtube.com/watch?v=0oszaqP0TI4 

the critical aspect being is it at the limit of its turn down range and then short cycling (which is inefficient). If it isn’t inefficient then the being over-sized is fine, but often isn’t.

Then forcing the cycling to effectively a shorter time on period would be a good first tactic. This would work best with high thermal mass, eg. UFH or solid brick house with good insulation. Aligning the on time to cheap electric is an opportunity.

5kW output at 12C OAT:

5kW unit is COP of 6.15

11.2kW unit is COP of 5.9

5kW output at -7C OAT:

5kW unit is COP of 3.0

11.2kW unit is COP of 2.9

The 11.2kW is the closest to double the 5kW in Mitsubishi's R32 range, the 6kW is a software limited 8.5kW so not a good comparison.

Comparing the Mitsubishi 8.5kW to the 14kW for an output of 8kW, at 12C and -7C, gives the same COP values.

So a larger unit running at approx. 50% vs smaller unit at approx. 100% doesn't seem to always result in greater efficiency. 

I would much rather have observational data from real world installation...   

  

Does anybody have any figures re the efficiency of heat pumps when under different loads?

Midea and I suspect other manufacturers do have detailed tables of heat pump outputs and i suspect it should in theory at least be possible to compare a higher rated heat pump running at lower capacity to a lower one running flat out. But it is complicated by all sorts of things, for example, the Midea 12, 14 and 16kW heat pumps are the same mechanically, the rating is achieved simply by capping the maximum output. That begs the question: at the lower outputs, are the all the same? At some point i may have a look and see what I can discern, but I have to say looking at those data tables makes watching the paint dry positively thrilling!

I see @jamespa has just posted on much the same lines.