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AC always active when fan is on?

Discussion in 'Gen 5 Prius Main Forum' started by Ronnie5, Jul 12, 2023.

  1. Ronnie5

    Ronnie5 Member

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    If the AC button is off, and the AUTO button is off, and I turn the fan on, I would expect the system to blow ambient temperature air from inside or outside depending of if recirculated or outside air mode is selected. As soon as I click the fan on, the temperature adjustment number appears, and it seems the system will blow cold air if the temperature selected is low enough. I would think that turning the fan on without AUTO or AC selected wouldn't even show the temperature adjustment number. Is this normal?
     
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  2. DoubleDAZ

    DoubleDAZ Senior Member

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    If the outside temp is lower than the setting, my 2014 will turn the heat on unless I lower the temp to LO. If the temp is higher, obviously the heat won’t come on and neither will the AC if it’s set to Off. The only way I can get ambient outside air is the LO setting and there still might be some heat involved that I just don’t feel.
     
  3. Numtini

    Numtini Member

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    You're not alone. I've been wondering about this as well. Our climate is very moderate and most of the time I'd be happy with just outside air coming through the vents. It's really pretty irritating. I don't want to drive around with the windows down because it's noisy and my hair turns into a mess.
     
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  4. BiomedO1

    BiomedO1 Senior Member

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    It's normal operations in my 2021. Anytime the fan is ON, the set temp is displayed. As stated earlier; If the air temperature coming into the cabin is lower than set point; it will heat up the air. You'll really feel it, if the engine is running, slightly warm air - if it's only the heat-pump. You may get an initial blast of cool air - residual from heat-pump operations. If the AC button isn't lit, it won't cool the air.

    Hope this helps.....
     
  5. Ronnie5

    Ronnie5 Member

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    Yes. Your description is how it works in every car I've driven. But not the 2023 Prius. It's going to get hotter here this week, so I'm going to stick a thermometer in the air vent and attempt to confirm it's cooling with AUTO and AC off.
     
  6. Trollbait

    Trollbait It's a D&D thing

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    With this system, AC can still be on while the AC button light is off.
    AC Button Light | Page 2 | PriusChat
     
  7. Ronnie5

    Ronnie5 Member

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    So, if I'm understanding your description of how it works, if I want the fan to blow outside air at ambient temperature, I should press AUTO, then press AC twice to deactivate, then press the outside air button, and then adjust the fan to my preferred level. Basically I need to be in AUTO mode, but override everything, right?
     
  8. aforkosh

    aforkosh Active Member

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    Forget about using AIUTO. Set the temperature to something below ambient and hit the fan speed button to trun on the fan and set the speed. Make sure that the air is being directed toward your body and not the feet and that the flow-through icon is selected rather than the recirculate button. Also make sure the A/C light is not on.

    One difference between Gen 4 and Gen 5 is that if you pressed Auto, you could see the state of all these things on the screen. You could also choose also easily toggle between Eco and normal settings for Auto control. Now to switch between them, you need to change settings via the multi-media screen or play with the settings in Custom Drive mode.
     
  9. bisco

    bisco cookie crumbler

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    what a nightmare
     
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  10. Chimera1978

    Chimera1978 Junior Member

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    There is a setting on the multimedia system to turn AC on automatically when AUTO is on.

    Incidentally, I did confirm today that having AUTO on and AC off did not blow cold air no matter what temp I set it to.
     
  11. Hammersmith

    Hammersmith Senior Member

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    It really isn't. People are making this way more complicated than it actually is in real life. For 99% of us, you just leave it alone and let the car do its thing. If you don't like to have the car controlling when the A/C is on or not, you make that one change in the settings and then control the A/C yourself. If you just want to override the climate control for a rare event, you just use the buttons on the dash to override whatever element you want at that moment, then press AUTO when you want the car to take back full control.


    Regarding what the OP was asking about, my instructions would depend on whether they want this just occasionally, or whether this is a regular desire. If it's a fairly rare case, I'd just press the vent button and then the A/C button twice and also make sure the temp setting on the control is below the outside temp(so the car doesn't start heating the air). If this is something they want all the time, I'd suggest disabling the A/C with AUTO option in the settings to save button presses in the future. That way they'd just make sure the A/C light was off and then hit the vent button to be certain it's not in recirculate.
     
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  12. Ronnie5

    Ronnie5 Member

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    Exactly. It works fine 99% of the time, it's just a bit annoying that it's different than most cars and not super intuitive. If the system is off, and I click the fan button to level one, I would expect it to turn the fan on and nothing more. Instead, it activates the climate control and doesn't light the AC light. I live in a mild climate, so often I just like some outside air so it's not stuffy. Now that summer is here, I'll be using the AC for a few months.
     
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  13. Trollbait

    Trollbait It's a D&D thing

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    Most of the time I'm fine with just air blowing without AC, and have always found auto AC systems a hinderance to that. Turn the AC button off in the Subaru, and the auto system can still decide to turn the vent to recirculate on a warm day. :sick: Went 7 miles wondering why the air blowing out of the vent seemed to be getting warmer than the outside when I got into the car before I caught that.

    If I have to have auto AC, I want one that I can set to X degrees above or below outside.
     
  14. Preebee

    Preebee Senior Member

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    I've not noticed any problems with just setting it to AUTO and letting it sort the rest out. In my G4, I had to crank the fan to adequately cool myself. But I was on ECO all the time, and that's supposed to be less-than-best AC. The G5 seems much more effective (could be due to the smaller cabin).

    Speaking of ECO, your climate control will switch between ECO and non-ECO depending on what drive mode you are in. If you are in ECO drive mode, your AC will be set to ECO. Just read this in the manual last night. :)
     
  15. Numtini

    Numtini Member

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    My grief with being unable to fully disable the AC is that I'm in a Prime and would prefer not to drain the battery unnecessarily running the heat pump.
     
  16. BiomedO1

    BiomedO1 Senior Member

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    FWIW; you can't fully disable the AC because it's a heat pump. If you don't want to prematurely drain the traction battery, Set your temperature on LO. It will only blow air, in manual mode, and won't activate AC or heat; unless you turn it on. If you do this; you should crank up to temperature set, when you do engage AC - otherwise you'll be running max. cooling and really drawing down the battery.
    I prefer to run mine in manual mode @ 68 degrees. I'll get some heat on early morning commutes, but I'm usually on the highway and prefer the cabin doesn't get uncomfortably cold. We've already gone through our first heat wave of the season. System performed great and cabin pre-cooling is working great.

    Hope this helps.
     
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  17. Numtini

    Numtini Member

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    Ok, to get pure vent rather than AC, it seems like you can turn off auto, turn on the fan, switch to exterior air, then toggle the AC button on so it lights up, then off again. I may be wrong about that, but it seems to be doing it.
     
  18. Mendel Leisk

    Mendel Leisk EGR Fanatic

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  19. bisco

    bisco cookie crumbler

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    it's going to be hard moving on from my gen 3 driver controlled everything. i know it's mental, but i'm mental
     
  20. BiomedO1

    BiomedO1 Senior Member

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    You're overthinking it - you shouldn't have to toggle the AC at all. The temp display will light up as soon as the fan comes on. Heat pump is still off, unless air coming in is lower than that set temp. (heat function will kick on - that's why you need to set temp to LO; that will disable the heat function).
    I've found that the car is more efficient in HV mode, on the highway. I do a manual switch-over and kick back to EV on city streets. I average over 150 mpg on my 40 mile round trip commute - No charger at work. Allowing the car to manage everything averaged 115 mpg; but I'd drain the battery on the highway and was mostly on gas, home bound in stop & go traffic. Works a lot better in EV mode, in that situation. Just experiment with it and enjoy the ride.