[Steve in Denver]

Why aren’t heat pumps standard equipment in the Niro PHEV? I understand that my 2022 PHEV has an electrically powered A/C compressor, so why not a heat pump, too? I have heard many times that (at least for home A/C systems) it only takes a few small changes to turn A/C into a heat pump. I’m not saying this could be done as a field modification, but during design / manufacture.

If that’s true of a home A/C, why not a car A/C? Does it require higher capacity parts? (Motor/compressor/condenser etc) or is there some fundamental difference in a car system that makes it nontrivial to convert a/c to a heat pump?

 

[atc98092]

More than likely simply to keep costs down. They don't even include a more conventional electric heater on the PHEV, so the ICE is required for any cabin heat. That said, it only runs the engine at a fast idle and actually adds a bit of a charge back into the battery. Because of that, my winter EV range was just as good as in the summer, with 30 miles being my average. For 2023 Kia is adding an electric heater to the PHEV, along with the larger battery and more powerful EV motor. With those changes, I might move back to the Niro PHEV when I get out of my Bolt lease.

There is much more to it than simply running the A/C in reverse. That's just a simplified way to describe the function. I don't believe there's a "simple" way to turn a home A/C unit into a heat pump either.

 

[stargate125645]

For 2023 Kia is adding an electric heater to the PHEV, along with the larger battery and more powerful EV motor.

Really? They didn't even do that with the EV6 or Ioniq 5, so this would be a nice surprise. In super cold weather, though, we'll need the ICE as I imagine it wouldn't be a robust heater?

 

[atc98092]

They didn't even do that with the EV6 or Ioniq 5

Every EV on the market has an electric heater. Some have heat pumps in addition, and they provide heat on all but the coldest days. I never fully understood if a Tesla with a heat pump still has an electric heater for backup. The information seems ambiguous. But the EV6 and Ioniq 5 absolutely have electric heaters, even if they also have heat pumps.

 

[stargate125645]

Every EV on the market has an electric heater. Some have heat pumps in addition, and they provide heat on all but the coldest days. I never fully understood if a Tesla with a heat pump still has an electric heater for backup. The information seems ambiguous. But the EV6 and Ioniq 5 absolutely have electric heaters, even if they also have heat pumps.

Haha I was thinking of the Tucson and (presumably since not yet released) Sportage PHEVs. I'm not sure why my brain went to the full EV ones - of course those have cabin heating abilities separate from an ICE.

 

[Mal]

Haha I was thinking of the Tucson and (presumably since not yet released) Sportage PHEVs. I'm not sure why my brain went to the full EV ones - of course those have cabin heating abilities separate from an ICE.

The PHEV has an electric heater but it's only 1kw which is only enough for defrost. It has an internal combustion engine and an efficient way to extract what is waste heat, (from exhaust and coolant). Heat pumps loose efficiencies at low temps which necessitates additional heat. The 1kw heater wouldn't do much and the small battery won't eather so all that's left is the engine. It does charge while heating so some of the inefficiencies are made up. The pure EV has no choice when the heat pump looses efficiency due to low Temps. It has to use electric heat. The big battery makes that feasible.

 

[atc98092]

My Bolt shows about 7 kW when the heater kicks up to full power. That would really zap the current PHEV range (has a pretty significant hit on my Bolt as well). The 2023 has a larger battery (over 11 kWh), which should soften the impact a bit. Also, don't forget that the heater doesn't run at full speed all the time. Once the interior has warmed, I rarely see it draw over 3 kW.

Modern automotive heat pumps have gotten much more efficient, and can produce usable heat down into the single digits (F). Here in the Seattle area, the heat pump would likely provide enough heat for all but the worst of winter days here. The heat pump only consumes about the same power as running the A/C, so seldom more than 2kW or so.