[jayofdoom]

In those hybrid systems, you only need the electric heating elements when the temperature outside is extremely cold. In the average winter season, my auxiliary heat, the electric furnace, runs less than a dozen times a year. The rest of it is all handled by the heat pump.

[voisin]

> when the temperature outside is extremely cold

Thanks to improving refrigerant technologies, the “extremely cold” threshold is getting lower and lower over time.