Revisiting the A/C on while on auto

[jmueller065]

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...

 

[studio460]

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.

 

[jmueller065]

For reference: My commute in consumed 5.7 kWh (according to MFM) over 16 miles.

 

[studio460]

I seem to average about 8 kWh for a 31.6 mile in-bound commute with only AC.

 

[davideos]

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]

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.

 

[NightHawk]

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.

 

[WattsUp]

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.

 

[jenjc]

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

 

[studio460]

My AC seems to be active even when the AC button is turned OFF. Fan is on LO, AC off, and still cold air seeps through. I have to turn the entire climate control system power button off to get the ice-cold air from "leaking" out of the vents (plus, I still have some air coming out of my lower vents when set to top-vents or defrost only--is this a vacuum, blend-door, or a ducting problem?).

 

[davideos]

From time to time when messing around with the climate control, I have seen that when the set temp is lower than the ambient and I have the AC off, the air is cold and I see the power consumption of the climate control to go up. This sometimes happens when I turn the climate control on by pressing the "low fan speed" button. I'm attempting to get outside air, not conditioned. I believe it works to press the AC button to turn it off eventhough the AC light comes on; but I usually just turn the system off and back on again, put the system on low fan speed and turn the AC off.

I haven't played with it in awhile, but next time it happens I'll take better notes.

 

[WattsUp]

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?

Apparently so. Unlike the A/C, there is no way to turn off the heat if, when you turn on the climate control, it thinks the cabin is colder than the ambient temp.

 

[WattsUp]

From time to time when messing around with the climate control, I have seen that when the set temp is lower than the ambient and I have the AC off, the air is cold and I see the power consumption of the climate control to go up. This sometimes happens when I turn the climate control on by pressing the "low fan speed" button. I'm attempting to get outside air, not conditioned. I believe it works to press the AC button to turn it off eventhough the AC light comes on; but I usually just turn the system off and back on again, put the system on low fan speed and turn the AC off.

I haven't played with it in awhile, but next time it happens I'll take better notes.

Sounds very odd.

With my FFE, it's been my experience that, when the A/C light is on, that is only time the A/C is actually on. By "experience", I mean feeling cold air and also seeing the corresponding energy usage.

What version of the MFT software do you have? I had some climate weirdness before updating to 3.6. Now is seems to work pretty consistently.

 

[jmueller065]

Put it on "LO", A/C off, and manually select the fan speed.

"LO" isn't exactly a temperature setting, it simply means don't heat (or cool if the A/C is off).

If you note that your climate is consuming ~1.5kW and it says A/C off: toggle the A/C on and then back off--in some cases the A/C will come on even if it says off on the display.

 

[WattsUp]

"LO" isn't exactly a temperature setting, it simply means don't heat (or cool if the A/C is off.

It sorta seems to behave like a temperature setting, around 60. If the outside temp is quite cold, the A/C stays off when I turn on the climate via "fan low". If the outside temp is warmer, the A/C comes on automatically.

 

[davideos]

From time to time when messing around with the climate control, I have seen that when the set temp is lower than the ambient and I have the AC off, the air is cold and I see the power consumption of the climate control to go up. This sometimes happens when I turn the climate control on by pressing the "low fan speed" button. I'm attempting to get outside air, not conditioned. I believe it works to press the AC button to turn it off eventhough the AC light comes on; but I usually just turn the system off and back on again, put the system on low fan speed and turn the AC off.

I haven't played with it in awhile, but next time it happens I'll take better notes.

Sounds very odd.

With my FFE, it's been my experience that, when the A/C light is on, that is only time the A/C is actually on. By "experience", I mean feeling cold air and also seeing the corresponding energy usage.

What version of the MFT software do you have? I had some climate weirdness before updating to 3.6. Now is seems to work pretty consistently.

I've got V3.6.2. The issue doesn't happen too often, and isn't too annoying, but it is there. I'll bring it up the next time I run into it.

 

[hybridbear]

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? Monitored diagnostic messages on the vehicles data link and saw that the A/C was on?

That's how I know in the Energi. The Energi will turn on the electric heating element if you turn the HVAC temp warmer than the ambient temp even with the A/C on. The Fusion Hybrid would just slowly move hot engine coolant through the heater core to blend hot air with cold air. The Energi will turn on the electric heater to do this.

 

[Gigi]

If the climate is set to LO and the AC is (supposedly) off, the compressor will run if none of the vent settings have been selected. Oddly, selecting the panel vent turns off the compressor.

 

[WattsUp]

"LO" isn't exactly a temperature setting, it simply means don't heat (or cool if the A/C is off.

It sorta seems to behave like a temperature setting, around 60. If the outside temp is quite cold, the A/C stays off when I turn on the climate via "fan low". If the outside temp is warmer, the A/C comes on automatically.

Earlier this last weekend, at the time of a late evening drive, outdoor temp (according to the car) was 54. I turned on the climate using the "fan low" button and the A/C stayed off. Later in the weekend, outdoor temp was 65. I again turned on the climate using the "fan low" button and the A/C came on.

I swear there is a temperature "threshold" that controls whether the A/C comes on automatically. It doesn't seem to be exactly 60 (because I've had the A/C come on when the outdoor temp was just below 60), but it certainly seems to be around 60, which is the lowest temperature you can dial in before the display just says "LO". (Perhaps "LO" is sort like dialing in 59?) I think, for me, the reason the A/C comes on automatically most of the time is because the outdoor temp is usually well above 60.

Does anyone live in a climate right now where the outdoor temp is commonly well below 60? If so, what is the typical behavior of the A/C when you turn on the climate control using the "fan low" button? Does it stay off ("A/C" indicator does not come on, no energy consumed) or come on ("A/C" indicator lights up, energy consumed)?

 

[dmen]

Wattsup:

The high temp here was about 50; cloudy all day so no solar radiant warming of the cabin. When I turned on climate control set to LO auto with no vent override, A/C defaulted to off, and climate graph showed no power draw. I have seen A/C default to 'on' in the same settings when the ambient temp was high 60s or above. So yeah, ambient temp seems to be taken into consideration in determining what LO does. But it's not like a numeric temp setting in the important detail that the heater should never be engaged in LO. If you set it to 60 and it's 20 degrees outside, the heater will run. If you turn it down one notch to LO, the heater will turn off. Same goes for HI. If it's 110 degrees in the car, HI will still turn on the heater. LO only cools, with cold outside air or a/c-chilled air; HI only heats; all numeric temp settings will heat in some settings and cool in others.
Other observations:
In cold dry weather, when I have climate set to LO and then select defrost vents, the climate power draw bumps up to 1 kW for a minute or so, then waxes and wanes every minute or so. It's presumably toggling the A/C, though the A/C indicator shows itself off. If no vent is selected or the panel or floor vents are selected, climate energy use remains 0.
I also think humidity plays a role in how the climate control chooses to act in LO. On a 55 degree very wet day, my LO with A/C supposedly off climate power draw was 1-2 kW with no vent, defrost vent, and floor vent selected. Only panel vents used no extra power.

I would guess these controls behave identically in Ford ICE cars. I know simple cabin heating is a much larger energy draw than the occasional unwanted A/C use, but I would still like to see a climate control system that makes more sense in an EV. A more efficient heater would be huge; an electric windshield defroster, an A/C off setting that does what it says and doesn't reset randomly, and a simple one-button 'outside air vent' would help as well.