alt Hacker NewsBeyond the other better insulation comments, pairing electric with heat pumps that are SEER 10+ goes a long way to improve heating efficiency. Old resistive heaters are 1:1 on energy to heat, while newer heat pumps operate to much lower temperatures, and give you 1:10 or 1:15 electric:heat energy ratios.
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That's not even close to correct. At the design lowest temperature (if <15°C), the very best get 2 COP, but most are 1.5 or lower. The problem is you have to accommodate the worst case.
The average of installed units is closer to 2.0 COP average, unfortunately. Multi-head units really drive down efficiency. A single-head Gree Sapphire can do 4-5 COP on average and that's the best you can get, so still nowhere near your guess.
> 1:10 or 1:15 electric:heat energy ratios
Under what circumstances? I've seen higher-end units that do maybe 1:5 in ideal conditions (heating to 68F when the ambient temp is 55F), but never seen units that do 1:10 or 1:15. This was about 2-3 years ago I did this research. Have things improved that drastically in the last few years?
My heat pump is SEER 19, and it can't heat my house below 25F. I think this is mostly due to it not being large enough - it was sized to cool my house on the hot summer days, and more energy needs to move on the cold winter days.