jmueller065
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Revisiting the A/C on while on auto

Wed Oct 22, 2014 3:41 am

For those of you who've reported that the car turns on the A/C while in auto (and it is clearly cold outside requiring heat): How do you know that it turned on the A/C? (Cold air from the vents? The Climate power consumption only reading ~1.5kW? Monitored diagnostic messages on the vehicles data link and saw that the A/C was on?)
I'm asking because today I figured I'd do a little experiment (a comfortable one at that): I left the HVAC in auto at 73F for my entire 15 mile commute in to work this morning.
What I observed doesn't fit with other observations. In my case the climate consumed 5+kW for a few minutes (after doing a precondition to 72F) and then the climate consumption dropped to the 1.5kW - 2.0 kW range and stayed there for the rest of the commute. (It was 45F outside so the incoming air had to be heated.) There is no way the car ran the A/C for the rest of the commute to cool the air.
If your observations are simply due to the power consumption level (during the summer the A/C by itself seems to consume the same 1.5kW - 2.0kW). Is it also the fact that you've felt cool air coming out of the upper vents? (In my case I did notice cool air coming from the upper vents but warm air was also coming from the lower vents.)
I can think of a few reasons for the power consumption:
  • - Perhaps it *is* using the A/C like a heat pump in a reverse cycle
    - There are two heating elements in the car, perhaps once its up to temp it only uses one
    - Perhaps it can modulate the use of the heating elements (maybe they aren't a full on or full off)
Just some thoughts for discussion...
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studio460
Posts: 281
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Re: Revisiting the A/C on while on auto

Wed Oct 22, 2014 4:02 am

Good question. I've been leaving my AC either on LOW (i.e., coldest setting), or OFF, so that I didn't activate any heating elements. At times, I would like to modulate the temperature to something like 68 or 70 degrees, but feared I would burn up too much kW.
2014 Ford Focus Electric, Oxford White/leather; Ford splash guards; ST replica spoiler, matte-black; de-badged.
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jmueller065
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Location: Southeastern MI
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Re: Revisiting the A/C on while on auto

Wed Oct 22, 2014 4:39 am

For reference: My commute in consumed 5.7 kWh (according to MFM) over 16 miles.
2018 Cajun Red Chevy Bolt
2016 Magnetic C-Max Energi (lease returned)
2014 Sunset Escape
2014 Thor Axis (V-10)
2013 Focus Electric (lease returned Jan 2016 for the C-Max above)
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studio460
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Re: Revisiting the A/C on while on auto

Wed Oct 22, 2014 4:41 am

I seem to average about 8 kWh for a 31.6 mile in-bound commute with only AC.
2014 Ford Focus Electric, Oxford White/leather; Ford splash guards; ST replica spoiler, matte-black; de-badged.
Lamin-X smoked reverse-light tint/blued headlight tint.

cwstnsko
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Location: Winnipeg

Re: Revisiting the A/C on while on auto

Wed Oct 22, 2014 5:01 am

The only reason I have found to turn AC off is to prevent the climate control system from cooling the car down to the set temp (70) after I have pre-conditioned it to a higher temperature (72) on a cold morning. Even then, the impact on energy consumption is very minor as the car fairly quickly drops below 70 and the climate control energy use settles in to the 1.25-1.5 kW range similar to what you observe. I don't think the AC is acting as a heat pump, but I'm not sure if the car actually engages it to dehumidify unless you have air ONLY directed to the windshield. When I have it set to a blend of windshield and some other setting, it seems that it may not be engaging the AC unless cooling is called for.
Chris W
2015 C-Max Energi, Magnetic, 302A package
2014 Focus Electric, turned in at end of lease

davideos
Posts: 406
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Location: So Cal

Re: Revisiting the A/C on while on auto

Wed Oct 22, 2014 5:47 am

My vote is #3, "- Perhaps it can modulate the use of the heating elements (maybe they aren't a full on or full off)". On a hot day, the AC will also take much more 1.5 to 2KW at first, and then drop down as the car reaches temperature. I figure the heating element does something similar.

WattsUp
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Location: SF Bay Area, CA

Re: Revisiting the A/C on while on auto

Wed Oct 22, 2014 10:30 am

jmueller065 wrote:For those of you who've reported that the car turns on the A/C while in auto (and it is clearly cold outside requiring heat): How do you know that it turned on the A/C? (Cold air from the vents? The Climate power consumption only reading ~1.5kW? Monitored diagnostic messages on the vehicles data link and saw that the A/C was on?)
When I've complained about this, I mean the A/C indicator in the climate control display lights up.

I think the A/C comes on whenever you turn on the climate control if the ambient temperature is above the set temperature on the controls.
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NightHawk
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Re: Revisiting the A/C on while on auto

Wed Oct 22, 2014 12:19 pm

Sometimes if the outside temp is reasonable (low 70s) I just want the fan on low without A/C on.
I assume turning the A/C button off and adjusting the fan speed manually would do that.
2014 Ford Focus Electric - Oxford White, Cloth Seats (Lease ended 9/28/2017)

WattsUp
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Joined: Mon Jan 07, 2013 2:58 am
Location: SF Bay Area, CA

Re: Revisiting the A/C on while on auto

Wed Oct 22, 2014 12:53 pm

NightHawk wrote:Sometimes if the outside temp is reasonable (low 70s) I just want the fan on low without A/C on.
I assume turning the A/C button off and adjusting the fan speed manually would do that.
Yeah, it does.

But, apparently there is no way to turn on the climate controls without the A/C coming on automatically in this case (that is, where the ambient temp is higher that the set temp, which would usually be "LO" when you just want fan). I think the A/C would stay off if the ambient temp was very low (lower than whatever "LO" is) like in the 50s or 40s. But, that's not normally the case where I live, except may on cold winter days or nights.

I routinely leave the temp set to "LO", and usually turn on the climate control (to get fan) by pressing the low-speed fan button. This makes the fan come on at the lowest speed setting, but almost always also turns on the A/C. So, I then have to do a second step of pressing the A/C button to turn it right back off.
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jenjc
Posts: 21
Joined: Wed Sep 10, 2014 4:06 pm

Re: Revisiting the A/C on while on auto

Wed Oct 22, 2014 3:36 pm

This may be a stupid question... but....

We took delivery on our FFE last weekend. Temps have been lovely here in ATL. No need for heat or A/C.

I already figured out how to simply flow ambient air through by setting to LO, putting the fan on the lowest setting and turning the A/C off. This works great in the afternoon.

In the morning, when ambient temps are in the mid-40's, I don't want or need heat (I'm assuming that LO is higher than the mid 40's), but would like air flow. How do I do this? Open a window?

Sometimes I do miss the old fashioned I-determine-exactly-how-I-want-it system. Select "Fan". select "Speed". Select source (vent, feet or defrost). Done.

Jenny
2014 Ice Blue Metallic
Delivery October 2014

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