My heat pump works well below 16 degrees

was your car in a garage or outside all night

 

I think you are making an invalid assumption. Some things are just not possible.

What source of heat is supposed to take over when the heat pump is not capable of producing heat ?
You are assuming that it is the engine.......but it could be a heat strip running off the HV battery.

 

The manual says it's the engine.

 

Ist day in the past 16 days that we have been above freezing here. EV driving today.

 

send it up here @huskers

 

The previous generations had ~800W of electric heating elements in the HVAC. I haven't found the same in the Prime electrical diagram. It does show a battery heater.

Bob Wilson

 

there has been no improvement to 'the system' (heat pump) because prius never had a heat pump before.
has anyone else tested this out? i'm not that surprised, the 14 degree number is unlikely a strict cutoff, and may depend on other factors.

 

I've run the heat pump down to 12F, but haven't had a chance to test it below that.

 

Today is the first day for us, in the past 2 weeks to get up above 0F. It has been -1F to -20F for the past 2 weeks.

The 12v battery on my Prius plug-in died when it first saw -10F. So I had road-side assistance come out and jump the car to get it going again. It is still under warranty, so the jump was 'free' to me.

In negative F temps the heat-pump does not work well, not at all.

Today on the ride to church, it kept the ICE running the entire trip. When we got back home, I still had the same level of charge in the drive battery as we had when we first got in the car this morning.

 

Micro climate. Snow blanket insulation. Wind shielded. Shaded from black sky cooling. Heat gained from nearby structure and its foundation. Buried septic system. Dryer vent. High water table. Location matters.

 

on a Prius plug-in?

Generally, want to keep septic away from a Prius.

 

My experience has been that with outside temp in single digit, climate prep does not warm up the car much. I have tried for 30 min with no cabin temp rise. If you continue to push remote A/C eventually temperature does go up after more than 40 min of climate prep, but it is like from 6F to 24F with 50 min continuous climate prep. Nowhere close to what OP has observed.

 

i drove the nine miles to church and back at 9 degrees with no heat. i would kill for a heat pump, but then my battery would be too small.

 

In order for a "heat pump" to deliver heat, it must be able to "extract" some heat from the outside air.
At 10 F there is precious little heat there to be had.

If Toyota has really learned how to make a heat pump produce a 90 F output with a 10 F "input", and without any resistive electric help, then a really LOT of land-based heat pump makers would be beating down their door.

 

with an in home heat pump, you are comparing efficiency with standard heating systems. in the prime, efficiency falls second to having the engine come on.

 

Huh......what ??