3 ms·

> The prototype delivers 100% heating at 5°F at double the efficiency, and 70% to 80% heating at -5°F and -10°F So, 2 EER (2x of resistive heat) at 5F, 1.8 at

> The prototype delivers 100% heating at 5°F at double the efficiency, and 70% to 80% heating at -5°F and -10°F So, 2 EER (2x of resistive heat) at 5F, 1.8 at -5F and 1.6 at -10F? Is that right? Seems awkwardly worded.

mlyle 4y ago
> So, 2 EER (2x of resistive heat) at 5F Yes (or double of previous model as another commentator points out-- hard to say). > 1.8 at -5F and 1.6 at -10F? They've not told us the efficiency-- just that it provides 70-80% of nameplate amount of heating at those temperatures.
- boardwaalk 4y ago
  Ah, I see. I figured they'd keep the input energy constant because otherwise you're not saying much at all (you could figure that the efficiency plummets and you'd be better off with a space heater).
  - mlyle 4y ago
    It's possible. Also possible it's barely outperforming the space heater at the lower temperature and input power has increased. They've not told us enough.
  - coryrc 4y ago
    The energy input goes down because it physically can't run a differential high enough to get full heating output. They could choose the lowest temperature, find it's power input, then fix it at that amount. But at low temperatures the concern is usually less "efficiency" and more "am I going to freeze to death", because in most of the cold areas temperatures aren't usually that cold for that long (though in others it definitely is, and if you're running at 1.6 COP for a significant amount of time, you're better off with more insulation than a heat pump).
hedora 4y ago
It says "double" the efficiency, so I assume they mean 2x the COP of the previous model at 5F, and 1.7-1.8x the old COP at -5 and -10F. A COP of 2 @ 5F isn't a "breakthrough" vs. the first commercially available model I could find numbers for, and a COP of 1.5 at -10F seems implausible: https://www.nordicghp.com/2017/01/heat-pump-effective-temperature-range/ https://www.nordicghp.com/2017/01/heat-pump-effective-temper... Honestly though, this press release is so poorly written, I wouldn't trust the numbers match up to anything.
brtkdotse 4y ago
That’s uh, pretty terrible? My 15+ year old Nibe gets as much

mlyle 4y ago

> So, 2 EER (2x of resistive heat) at 5F Yes (or double of previous model as another commentator points out-- hard to say). > 1.8 at -5F and 1.6 at -10F? They've not told us the efficiency-- just that it provides 70-80% of nameplate amount of heating at those temperatures.

boardwaalk 4y ago
Ah, I see. I figured they'd keep the input energy constant because otherwise you're not saying much at all (you could figure that the efficiency plummets and you'd be better off with a space heater).
- mlyle 4y ago
  It's possible. Also possible it's barely outperforming the space heater at the lower temperature and input power has increased. They've not told us enough.
- coryrc 4y ago
  The energy input goes down because it physically can't run a differential high enough to get full heating output. They could choose the lowest temperature, find it's power input, then fix it at that amount. But at low temperatures the concern is usually less "efficiency" and more "am I going to freeze to death", because in most of the cold areas temperatures aren't usually that cold for that long (though in others it definitely is, and if you're running at 1.6 COP for a significant amount of time, you're better off with more insulation than a heat pump).

hedora 4y ago

It says "double" the efficiency, so I assume they mean 2x the COP of the previous model at 5F, and 1.7-1.8x the old COP at -5 and -10F. A COP of 2 @ 5F isn't a "breakthrough" vs. the first commercially available model I could find numbers for, and a COP of 1.5 at -10F seems implausible: https://www.nordicghp.com/2017/01/heat-pump-effective-temperature-range/ https://www.nordicghp.com/2017/01/heat-pump-effective-temper... Honestly though, this press release is so poorly written, I wouldn't trust the numbers match up to anything.

brtkdotse 4y ago

That’s uh, pretty terrible? My 15+ year old Nibe gets as much