Is cabin heat "free" if a Prime is in HV mode?

For those of us who live in cold climates, driving without interior heat is not an option.
Nevertheless, heated seats and heated steering wheel are welcome.

 

Of course, it is not free if you turn on the A/C (heat pump), which uses a lot of electricity. But:

If you don’t turn on the A/C (heat pump), you can still get some heat from the heater core, which circulates engine coolant. Adjust the temperature to the desired heat. You can turn on the fan only without the A/C (heat pump) and still adjust the temperature. The fan alone should not use that much electricity.

I need to turn on the A/C (heat pump) occasionally in Southern California because the windshield fogs up. I then set it to DEF vents. It is more efficient than using the DEF button, which is much more aggressive and also activates the mirror defoggers.

 

Studies have shown that people who put up with cold weather regularly live longer and stay healthy longer... And yes it is true the ICE heat is the most efficient source of cabin heating costing less than pennies on the dollar via what you pay as mpg.

One thing that could change this is battery pack temperature optimization. The battery runs most efficient at very specific temperatures. And being able to monitor that temperature and how efficient the car manages it versus you needing to manage is significant. It may well be that lots of cabin heat in cold weather improves EV range in some scenarios.

On one end of the spectrum you have a Prime like yours living in a heated garage and plugged in. On the other end of the spectrum you have a Prime like yours living on the street with no home charging in sub-freezing temperatures.

 

I owe the fact that I am still alive to the fact that I have tried to eliminate all stress in my life. Endlessly fine-tuning settings and driving habits to extract maximum fuel economy is not my idea of reducing stress. I am happy to take the benefits of driving my car normally. I know I am reaping an enormous benefit just by owning a Prius.

 

I believe the Prime has a heat pump so it still uses electric in Hybrid node.That is my guess. Otherwise in EV mode the heat pump would need to heat up engine coolant too, which would be counter-productive,

 

I don't know whether the Prime does include a conventional heater core as well as the heat pump. For purposes of discussion, let's assume it does.

The question is still a bit more involved than you're making it. If you have an OBD-II device you can plug in and watch live data, you can watch the coolant temperature. Whenever that number exceeds the thermostat-opening temperature, you have "waste heat" and you can use some in the cabin for "free". It would be going out the radiator otherwise.

In even a regular hybrid, you can often find the engine running with the coolant temperature not above the thermostat-opening temperature. At those times, your cabin heat is not "free"; every joule of heat you're taking out has to be made up from gasoline to maintain the operating temp.

 

Yes, in hybrid mode with a warm engine, the cabin heat comes from engine waste heat.
The car will also turn on the engine for that heat when it isn't possible for the heat pump to provide the required heat, like with the defroster turned on.

 

Also in Sub-Zero °f - temperatures the ice will turn on to assist for defrosting