Auto A/C settings

i think that electric heat was simply smaller lighter and easier to control.

im not sure but it seems to me that i read that a heat pump must pump a certain volume of air to be cost effective so its great for a house that remains at fairly constant temperature for long periods but a car would be too small. iow, the initial power output wouldnt be justified for the multiple short duration cycles that most cars would experience.

 

Good point. I hadn't considered all that...I just barely know how to spell Heat Pump.

 

Remember, the Traction Battery temperature is regulated by taking Cabin Air in through the vent by the back seat.

This is good, because the Traction Battery is happiest at about the same temperatures as people. Too Hot or Too Cold and it definitely goes into Goldilocks Mode.

So, I've always intuited that the supplemental Electric Cabin Air Heaters served two purposes.

First, it gets the Cabin Air up above frigid faster, thus helping not only you, but the Traction Battery to reach optimum comfort quickly.

And second, it can buffer the need for the ICE to come on to heat coolant to keep you and the battery happy.

Caveat: I of course have no actual knowledge of the Design Decisions or Computer Code Set Points involved in this any more than I do about how/when the Prius decides exactly when to spin each MG in any given direction