On Mon, 21 Oct 2019 20:58:53 +0100, "Commander Kinsey"
wrote:

On Mon, 21 Oct 2019 20:50:32 +0100, A noiseless patient Spider wrote:

On 10/21/2019 3:20 PM, Commander Kinsey wrote:
Why can't I find a heat pump with a good SEER rating? The USA has a law stating 13 minimum. Yet here in the UK, I looked at Panasonic and they're all 7 to 11!


It's because we use 120/240 volt 60 Hz two-phase. Your single-phase 50 Hz is less efficient.

https://www.energystar.gov/products/...rce_heat_pumps

I don't believe you. There is no way they can be twice as efficient with a different input voltage or frequency.

You are right and that guy is wrong on several things. To start with
we have single phase, just like you, just a slightly different
frequency. Conventional HVAC units run on 240v. It really doesn't
matter tho if the motors are optimized for the frequency. If you buy a
mini split it doesn't matter at all. They use inverter supplies and
convert the voltage to DC as soon as it gets inside. Then it is
converted to the voltage they need for the unit.