Winter operation of GM Volt

[john1701a]

Some enthusiasts are already disenchanted from learning that winter will require the engine to run, wrecking their "no gas ever" hope. Li-Ion requires warmth. Frozen from sitting in a parking lot without a plug available while you work for 9 hours means heat is needed quickly from something. Gas will be consumed to provide that.

Anywho, the problem gets worse (reinforces the clever design of Prius) when you ask the next question...

How will the system provide DEFROST for the windows in the winter?

If the A/C operates in reverse as a heat-pump to provide warmth, what will dehumidify the air so condensation doesn’t build up on the glass?

In both traditional vehicles and FULL hybrids, this is accomplished by running both the Heater and A/C at the same time. If Volt only has a single system available, how will it condition the winter air to deal with both cold & moisture?

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[FL_Prius_Driver]

Originally Posted by john1701a

How will the system provide DEFROST for the windows in the winter?

Possibly the same way Telsa does.

Originally Posted by john1701a

If the A/C operates in reverse as a heat-pump to provide warmth, what will dehumidify the air so condensation doesn’t build up on the glass?

In both traditional vehicles and FULL hybrids, this is accomplished by running both the Heater and A/C at the same time. If Volt only has a single system available, how will it condition the winter air to deal with both cold & moisture?

An electric heater is one of the simplest answers. Does GM have engineers that can get this right...Yes. Does GM have management that can force the wrong answers ....yes. Interesting to see who prevails.

[usbseawolf2000]

Hmm... Interesting question.... have to think about that.

How about run the electric A/C to condense air and the gas engine will provide the warmth?

If both A/C and heater runs on electric, the battery pack in cold temp will not put out enough juice to drive the Volt. It seems starting the gas engine is a must.

[efusco]

You know that Volt people will be just as creative as Prius people in developing work arounds. Heated garages are an obvious benefit.

I would guess that the defrost and heat will, by necessity, be electric.

[darelldd]

Originally Posted by john1701a

How will the system provide DEFROST for the windows in the winter?

If the A/C operates in reverse as a heat-pump to provide warmth, what will dehumidify the air so condensation doesn’t build up on the glass?

In both traditional vehicles and FULL hybrids, this is accomplished by running both the Heater and A/C at the same time. If Volt only has a single system available, how will it condition the winter air to deal with both cold & moisture?

Well, I drive a FULL EV, and my FULL EV works just like my Prius when in demist mode. It first dehumidifies the air with AC, then passes it to the heater which warms it for the cabin. All this is done with a heat pump system running on nothing but battery. Ever.

Originally Posted by FL_Prius_Driver

Possibly the same way Telsa does.

Or at least the way the Rav4EV does!

[john1701a]

Originally Posted by darelldd

It first dehumidifies the air with AC, then passes it to the heater which warms it for the cabin. All this is done with a heat pump system running on nothing but battery.

Are you saying that the "heat pump system" actually has two seperate components within or is there a continuously alternating process to first do one then the other?

Detail please.

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[qbee42]

Originally Posted by john1701a

Are you saying that the "heat pump system" actually has two seperate components within or is there a continuously alternating process to first do one then the other?

Detail please.

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The heater is a simple electrical resistance heater.

Tom

[john1701a]

Originally Posted by qbee42

The heater is a simple electrical resistance heater.

In what?

The question is specifically for Volt.

It's very important to be specific, since we're discussing a vehicle that's advertised with ideal-condition values. Winter operation certainly won't be, and we don't want to contribute to any misleading.

So... what I'm being told appears to be that coils will be used in addition to the regular cold/heat system when dehumidifying is also required at the same time. Correct?

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[qbee42]

Originally Posted by john1701a

In what?

The question is specifically for Volt.
<snip>

Rav4EV, as well as any other EV with heat.

While I don't have any solid information, it is almost certain that the GM Volt will use a resistive heater unit. A heat pump unit would fail to efficiently provide heat in real winter conditions, so some sort of backup heater is needed. If you have the resistive unit, in makes sense to use it for defrosting and defogging.

Tom

[daniel]

The EV that I'm hoping to get (seems to be on hold right now, but I'm still hoping... knock on wood!) will have an electrical resistance heater and a conventional A/C belt-operated from the electric motor. The A/C won't run while the car is stationary, but that's not a problem for me. Defrost will be by running both the heater and the A/C.

Since the Volt is a make-believe car that GM has no intention of ever building, it does not need a defogger. But if they're saying that it will have only one compressor for both heating and cooling, and no resistance heater, then they definitely need to change their ad campaign and say that the car they're pretending they're going to build will have resistance heating.

My Xebra has no A/C but it does have a powerful aftermarket resistance heater. It heats the car much faster than my Prius. When I lived in Fargo, at 20 below F the car took a good ten or 15 minutes to warm up. A resistance heater would heat a car a lot faster than the Prius manages it. And the LiFePO4 batteries in my Xebra do as well at zero Celsius as they do at 25 C. Not sure how well they'd do in Fargo. But that's a moot point for me because after 30 or 35 years on the northern prairie I couldn't take the cold any more myself. If they ever manage to invent those ultracapacitors, cold will no longer affect electric storage.

I don't know about Li-Ion batteries like in laptops and in the Tesla, but LiFePO4 is much less affected by temperature than are lead batteries, and LiFePO4 is not subject to thermal runaway, like Li-Ion batteries are.