Do you have a heat pump on http://HeatPumpMonitor.org with MID meters? If so, we need your help to compile real-world maximum output test data. We’re working on creating an open-source database of real-world heat pump maximum output and minimum modulation data, this will be very useful to ensure heat pumps are correctly sized: https://heatpumpmonitor.org/heatpump
Watch the video below for how to contribute. There should be some cold temperatures tonight and tomorrow. Thanks! 
Thanks to the owner of the 16kW Gen 7 R290 in Wymondham, Norfolk for submitting a nicely executed max output test today. Target temperature of 65C is safely above the achieved flow temp of 44C. Average output over 2 cycles 14.7 kW, 0.4C outside. Looks like humidity was around 66-70%? which is relatively low: Wymondham (Norfolk) last 24 hours weather - Met Office
The minimum modulation of around 4.8 kW suggests a nice modulation range 32% of max output.
Looks like this output is very close to the datasheet value of 14.7 kW at -2C or 15.3 kW at +2C. It would be interesting to see how it changes at 100% relative humidity.
Thank you to the owner of the 16kW Samsung Gen 7 R290 in Huddersfield, West Yorkshire for submitting another max output test for this unit today: 15.26 kW at -0.9C over 4 defrost cycles 
higher than the datasheet. Looks like relative humidity was 78-80% according to Met Office which is close to typical heat pump test conditions.
Thank you to the owner of the 9 kW, Octopus Cosy for submitting both a maximum output and a minimum modulation test result: https://heatpumpmonitor.org/heatpump/view?id=18. Looks like we are seeing a range from 7.1 - 8.0 kW so far and a minimum modulation of ~3 kW (about 40%).
Thanks also to the owner of the 7 kW, Panasonic Aquarea J of Utrecht, Netherlands for submitting a max output test of 5.5 kW which is also in line with previous submissions HeatpumpMonitor.org . With a minimum modulation of just under 3 kW the minimum modulation on this unit is not looking very high so far at 55%.
Thanks to @ColinS (my father in law!) for submitting a new maximum output test from his 11 kW Daikin Altherma R32 https://heatpumpmonitor.org/heatpump/view?id=48 at 12.1 kW! This result is particularly interesting as it is significantly above the output seen on earlier tests and follows a firmware update from Daikin. Colin noticed that the compressor now hits a maximum electrical consumption of 6 kW, a fair bit higher than the 5 kW or so seen in earlier tests, see earlier thread here: ASHP sizing for Freezing Conditions - #93 by TrystanLea . This result was at 80% outdoor humidity I believe, Colin is still seeing quite a variation with humidity.
Thanks Trystan, I have a working assumption that my 11kw model was firmware upgraded to a 16kw. The only differences in the Daikin 9 to 16 ‘range’ of models seems to be the fan and pump speeds. As my pump speed is limited I suspect the max fan speed has been raised. This does not fully account for a 1kw power input rise as the fan is rated at 234w and the pump 180w…. but it seems credible. Under defrost conditions the fan speed (or rather air speed over the evaporator fins and tubes) is likely to be the output limiting factor. If the dewpoint is say 2c below ambient then one way to keep frosting low, when the evaporator surface is 6c below, is to blast the air through so very little actually drops that 2c and so less water freezes out. Here’s the data table showing the fan differences.
I see you did add also minimum modulation data from my system. I was looking for specific instruction to do such test, I believe they are still missing? Or can you otherwise provide a link?
Update: trying to load some other example of minimum modulation I see at least one requirement: Outside temp needs to be => 10 °C
