Wise words!
The design decisions taken by the manufacturers have a surprising impact on what part of the operating envelope the carnot * %age of carnot figure is most favourable.
I generally compare my system CoP to the Daikin data book values. On the assumption that these were measured with a near-optimum system (e.g. not emitter limited), if Iâm close I imagine my system is probably working as well as can be expected.
Where do you find the âDaikin data book valuesâ unable to find in manuals I received.
There is some information in the âtechnical data bookâ, which should be findable (my unit is the EDLA08 so I canât just post it). I donât expect to get close to these!
I also used their capacity table viewer - CDC - which requires a login (but free to register). This gives power out and in at 100% capacity (use the integrated value), from which you can compute the CoP at 100% capacity, which is not really what is needed but it does at least give a guide. Efficiency will drop off as capacity is approached so you should normally be able to beat these values when operating at mid-load and look at the extent to which you are beating the value as a relative measure of how well tweaks to your setup are working (or not).
This is clearly imperfect and comparison against the Carnot CoP, as others have said, is worthwhile.
One other comment: I generally look at CoPs averaged over a period or when the system is in near-steady-state. Instantaneous values are misleading in non-steady-state conditions.