After a bit of research I have become a little confused with Mitsubishi:
Their add says:
While ordinary heat pumps produce less heat below 7°C, only HyperCore® guarantees its fully rated capacity right down to -15°C
1. Mitsubishi advertise their HyperCore Heat Pump as providing full power from minus 15 deg C.
2. They say other standard pumps do not even at 7deg C.
3. My room being 136 cu meters requires a power rated pump of 8.3Kw but Mitsubishi do not make a HyperCore pump of that size their max is 6.8Kw (MFZ-KJ60VEHZ)
4. In their “G series” they do make a pump of 9Kw (MSZ-GE80VAD) which seems the way to go and has low temp performance down to minus 15deg C’
This goes against their advertised benefits of HyperCore that “other pumps struggle at temps of 7deg C and lower” so if true is not going to be of much use in the winter.
I think their advertising of the HyperCore is really saying our other pumps are not that good at cold temps, yet the “other pump” advertising says good down to minus 15degC. ?????
I think the G series would do the job.