GerryAZ said:
Actually, the LEAF heat pump system (at least on 2015 model) has two heat exchangers in the duct work in the dash and can run one to heat the air while the other dehumidifies the air. Since I have had both 2011 with resistance heater and 2015 with heat pump, I can say that the heat pump is a great improvement in my climate.
Gerry
No. There are two heat exchangers but they never work simultaneously.
If HEAT and AC are both enabled (air drying in moist weather) compressor runs the AC (cooling, dehumidification) and PTC
heats the air after it has been dried. Aka it takes as much electricity as it takes on cars without heatpump.
Dehumidification is unnecessary and not possible in freezing weather. I've tried, doesn't work well enough.
Actually it is almost never needed. It is easier/more efficient to crank up the heat with heat-pump enabled vehicles.
Leaf with heat pump can generate 8-10kW of heat. That is more than enough to dry the windshield
Heat pump is not necessary if temperatures often drop down to 10C/50F and rarely drop below 4C/40F. Due to the fact that PTC
doesn't need a lot to heat the cabin moderately. Maybe this is why Bolt doesn't have it.
But near freezing the difference becomes bigger and bigger. Up to -10C/14F. 2-3x less consumption on heating.
Below -15C/ 5F heat pump is pointless. So it clearly depends on climate.
Estimations for warm Leaf cabin after warming up (w pump): 0C/32F - 300W, -5C/23F - 600W, -10C/14F - 1100W, -15C/5F - 2000W (PTC only).
Tesla doesn't have heat pump. Most likely the AC system is designed to be as powerful as possible in AC cycle. Because Tesla
does MAX out AC requirements in hot weather while SuperCharging. More is needed but that is not possible (no room for radiators).
I expect European version of Bolt and maybe even Model3 will be offered with reversible AC-system. It does make sense even more
if vehicle heats the battery to optimal temperature. Doing that at 200-400% efficiency saves on consumption while heating the pack.
Chevy tried very hard to keep the cost down. And, like I said, in warm climate, pump is not reasonable. Especially with 60kWh pack.
They will learn their mistake as soon as Canada or Europe starts to acknowledge Bolt as not 200mile EV on highway but rather 150 mile
EV for all year round use.
Driving for 3 hours in Bolt will draw 3x3kW=9kWh of heat in cold weather (14F). Aka 1/6th of the pack. At those temperatures heat pump makes sense.