Any idea why the HEATER draws so much POWER?

[jmueller065]

If you attempted to use something like a 1 kW space heater in a car in a very cold environment, I think you'd find that you're still cold. It might work okay in a moderate winter climate.

Actually I think my coworker is going to try doing just that! LOL He is going to plug in a ~500w inverter and use that to run a small space heater. I'll know in a few days how it went.

(He does use go times so his car will start out at 85F but his commute is close to an hour...)

 

[sefs]

A space heater is taking advantage of recirculation. The car's HVAC system cannot. It is always heating the cold outside air all the way up to cabin temperature. If you're curious why the HVAC system does not recirculate, just turn on recirculation and note the very rapid fogging of windows.

 

[WattsUp]

A space heater is taking advantage of recirculation. The car's HVAC system cannot. It is always heating the cold outside air all the way up to cabin temperature.

Not totally true, right? You can recirculate if you want (just press the recirculate button) to help the CC heat or cool the cabin more quickly, but you usually can't recirculate continuously with heat, due to the fogging issues you mention.

 

[sefs]

A space heater is taking advantage of recirculation. The car's HVAC system cannot. It is always heating the cold outside air all the way up to cabin temperature.

Not totally true, right? You can recirculate if you want (just press the recirculate button) to help the CC heat or cool the cabin more quickly, but you usually can't recirculate continuously with heat, due to the fogging issues you mention.

You can recirculate during heating, it just isn't sustainable due to fogging.

 

[hybridbear]

Remember that the car also heats coolant which then flows through the heater core to transmit heat to the car. A space heater at home uses a heating element and a fan to blow air across the hot wire. I'm not sure which system is more efficient.

 

[WattsUp]

You can recirculate during heating, it just isn't sustainable due to fogging.

Unless you turn on the A/C as well (to keep the air dry), but then you're using even more energy. This approach is workable in an ICE, less workable in the FFE.

 

[sefs]

You can recirculate during heating, it just isn't sustainable due to fogging.

Unless you turn on the A/C as well (to keep the air dry), but then you're using even more energy. This approach is workable in an ICE, less workable in the FFE.

Unfortunately, the A/C compressor won't turn on under 39.2F.

 

[NightHawk]

You can recirculate during heating, it just isn't sustainable due to fogging.

What if you coat your windshield with an anti-fog solution (diluted vinegar) to prevent fogging?

 

[sefs]

You can recirculate during heating, it just isn't sustainable due to fogging.

What if you coat your windshield with an anti-fog solution (diluted vinegar) to prevent fogging?

Anything is worth a shot. Running on recirculate would decrease energy use a good bit.

 

[EVA]

Does the car spend a lot of energy heating up the battery?

I think you would see this happen with really large wh/mi at the start (you didn't use go times to preheat the cabin and battery), and then settle in at a lower level after the battery was warm.

 

[sefs]

Does the car spend a lot of energy heating up the battery?

I think you would see this happen with really large wh/mi at the start (you didn't use go times to preheat the cabin and battery), and then settle in at a lower level after the battery was warm.

The battery heater is only engaged while plugged in. During driving, waste heat from the motor, inverter, and DC-DC converter are used to heat the battery.

 

[Tim Jodice]

How about using the existing battery as a thermal battery? Let's say the battery works best between 60 and 90 degrees and when you program it to preheat the car it heats up the battery to the top of its safe temperature range. In addition to making the battery probably have more capacity the climate control could pull heat from it. Given the weight of the battery I would think a 30 degree spread would be a useful amount of heat. To do this I think would be nothing more than a software update. Don't take the temp numbers as an absolute, I don't know what the safe range is.

 

[michael]

Ford could have, and I wish they would have, provided a more sophisticated thermal management system for the battery. Chevy did this for the Volt. Control the battery temperature more cleverly when plugged in. Tesla has patents (now available for everyone's use) on this subject.

My guess is that Ford didn't do this because it would reduce the MPGe rating. I wouldn't care, but there are some people who think MPGe is an important consideration in selecting a car. If you read the BMW and Spark forums, fanboys there boast about this.

That said, the use of a resistive heater rather than a heat pump is one reason I won't be replacing my FFE with another one.

 

[michael]

It wouldn't have cost them a cent to put better software in the TMS. Volt is in the same price class as FFE and does a much better job. They keep the battery temperature much more closely regulated.

I think the reason was to minimize additional power consumption while plugged in.

BMW and Nissan seem to manage well enough with heat pumps. If it's true that resistive heating is needed in very cold conditions, they why not provide the option for either one? Make heat pump the extra cost option if necessary...I'd go for it in a second! It seems to me that those living in cold climates need every bit of efficiency available...use resistive only when needed.

 

[triangles]

Actually it would be better if they replaced the electric heater with a combustion heater. Electric is too inefficient for heat. Maybe in 10-20 years when battery technology has improved electric heat might make sense. I had considered replacing the electric heater with a propane "parking heater" using the 1LB throwaway propane cylinders as my fuel tank. I suppose I could do a diesel one but I like a cleaner fuel. I haven't done this yet since range isn't an issue with my whopping 15mi round trip commute. That and the cost is north of $1k for one of these heaters.

For some reason people usually go stupid on me when I suggest this with irrational fears of explosions, giant fireballs, and death. Sure there's a fire hazard anytime you have combustible fluids/gasses. I guess people just fail to realize that gasoline is easier to ignite than propane and people routinely drive around with 10-40 gallons of gasoline underneath them daily.

 

[jmueller065]

Actually Ford's "Thermal Battery" idea sounds kind of intriguing:
http://www.technologyreview.com/news/513466/novel-heating-system-could-improve-electric-cars-range/

I wonder if they continued the research on it from a few years ago.