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HVAC Auto Setting

Discussion in 'Prius v Main Forum' started by Pmucho, Feb 9, 2015.

  1. Pmucho

    Pmucho New Member

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    I have a 2013 Prius v (lowercase v for the Prius v wagon, not an uppercase v) 5 and was wondering if the setting can be changed that automatically turns on the A/C when I press the "auto" button on the climate control. The A/C comes on now and I do not want it to.

    The owners manual does not address this topic but I have seen a You Tube video and other threads that shows how to override the setting. However, I cannot seem to get to that setting selection on the screen.

    Perhaps the ability to change the setting is only available to those who have the "tech package"... I do not have the "tech package".

    Or only available to non U.S. type vehicles. I have a U.S. vehicle.

    Or can this setting can only be changed by the dealer?

    Any help would be appreciated.
     
  2. bisco

    bisco cookie crumbler

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    what happens if you turn up the temp?
     
  3. Pmucho

    Pmucho New Member

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    This time of year (Chicago) I have it set at 78.
     
  4. bisco

    bisco cookie crumbler

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    what happens if you press the a/c button after hitting auto?
     
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  5. rdgrimes

    rdgrimes Senior Member

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    The A/C light is on but that doesn't mean the compressor is running. the only time it will run is if there's a call for defrost or its too warm inside. In short - it makes no difference whatsoever.

    That said, if you hit the A/C button and turn it off, the system remembers that till you hit auto again.
    Also note that setting the temp to 78 will burn quite a bit more gas to keep the coolant warm enough. Set it lower if you want to save some gas. You're burning FAR more energy keeping it hot than you ever will leaving the A/C engaged.
     
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  6. Pmucho

    Pmucho New Member

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    It goes off

    G
    Good advice. Thanks for the feedback.
     
  7. Tideland Prius

    Tideland Prius Moderator of the North
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    A/C doesn't mean cold air. An air conditioning system conditions the air. In the summer, that means cooling it. In the winter, that means drying it so that your windows do not fog up.

    If the AUTO light is on (or is engaged) with the A/C light on, it doesn't mean the A/C compressor is running, it just means you're allowing it to running automatically as needed. For example, the A/C compressor keeps the windows clear by running lightly in cold rainy west coast weather. The moment I close the vents (say, because I am following a diesel truck), the A/C kicks into higher gear to prevent the windows fogging up. If you don't have it engaged, the windows will fog up in a few minutes due to the recirculation of moist air (remember your breath and the snow you brought in adds moisture to the air inside the car).

    However, you can turn the A/C light off in AUTO mode so it'll never run but everything else is still running automatically as designed.

    OR you can also go into manual climate mode by adjusting everything manually (fan speed and MODE so that both fan speed and the MODE where the air comes out will be set to exactly where you left it).
     
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  8. kithmo

    kithmo Couch Potato

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    The AC still cools the air even with the heat on, it just passes the dry, cooled (and conditioned) air through the heater after the condenser.
    This of course means the cabin will take longer to warm up as you are now blowing cold air through the heater as opposed to ambient.
    AC on still has the advantage of drying the air, keeping condensation down.
    I don't know for sure about the Prius, but with most cars, if ambient is 4 deg C or less then the AC doesn't operate anyhow, to prevent the condenser icing up.
     
  9. jonb505

    jonb505 Member

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    I think that partly explains why my winter mpg is worse since moving to Vancouver 2 years ago from Edmonton. I leave my climate control on auto all the time. I just set the temperature and let it do its thing. In Edmonton during the winter even on those -30 days I never did worse than 42 mpg.
    In vancouver where it rarely ever drops below freezing but rains a lot in the winter I average around 36mpg. I'm thinking the ac is working harder in Vancouver year round to keep the humidity under control, compared to the dry climate in Edmonton.
     
  10. rdgrimes

    rdgrimes Senior Member

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    The A/C isn't costing you a penny in MPG. The compressor barely runs at all in that situation, and only at its lowest speed for a minute or so at a time. All it has to do is lower the temp of the coils just enough to create condensation. Even in 100' heat, running full blast, the A/C *might* cost you around 2MPG.

    People need to get old ways of thinking out of their heads. This is not the A/C system of years past. Its a multi-speed electric compressor that's designed and computer controlled to very tight specs with the purpose of minimizing current drain. Use of the ECO system mode even further reduces the drain. But at its lowest speed, that compressor can run a VERY long time without draining the traction battery. The impact on MPG is negligible, if its measurable at all.
     
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  11. Tideland Prius

    Tideland Prius Moderator of the North
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    Don't forget terrain and speed limit differences. Vancouver has lower limits (50km/h vs. 60km/h) on surface streets and the hills don't help unless you average them out over a longer commute to take advantage of rolling terrain.

    It'll run more if people keep it in recirculate. You can smell the difference (there's that A/C compressor smell when you close the vents on a rainy day).

    If you want to know if the A/C compressor is running, stand beside the front passenger headlight. The A/C compressor is quite noisy and you'll hear it when it kicks in. (Running the Remote A/C in the summer when the car is off, it sounds like a lawn mower)
     
  12. Mendel Leisk

    Mendel Leisk Senior Member

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    This is on a 2010 Prius hatchback, so not sure how relevant, but anyway:

    If AC button is not pushed (light on button off) and I push Auto button, AC continues to be off. The ONLY* time I've observed AC come on, when not requested, is if I set mode to Heat/Defog. Then it will run AC intermittently, under some conditions. It doesn't light the light on the AC button, but my ScanGauge shows AC wattage dancing between various values, zero to maybe 200. If ambient temp is low, near freezing, AC still stays off, even in Heat/Defog mode. If ambient temperatures are higher, AC may come on. I'm not sure what the parameters are, might be it's sensing humidity, but I'm really not sure.

    * Barring pushing Front Defog button, which always switches on AC, and lights the light on the AC button as well.
     
  13. jonb505

    jonb505 Member

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    I agree tideland, the hills in my commute among other factors(traffic) likely are the main cause of my mpg drop.
    I didn't know that about the AC rdgrimes, although i kinda figured the AC system in the Prius was especially efficient just as the rest of the car is designed to be.
    I guess i was going off the way AC was used in the old family cars growing up. My parents would use it very sparingly just to take the edge off the heat, and they would rather open the windows or sweat it out than run AC figuring it wasted lots of gas. They still do it today in their 3 year old non hybrid car, which i'm sure is more efficient than cars 10-15 years ago. I guess old habits die hard as they say.
    :rolleyes:
    I've even had people riding in my car during the summer a couple of times see the AC light illuminated and turn it off for me(they felt it was too cold and thought i had absentmindedly left the ac on full blast). Then I tried to explain to them i would just turn up the temperature on the climate control system and the ac would only run as needed as it was automatically controlled.
    I think its a misunderstanding/mistrust some people still have of automatic climate control systems in general. Just set the temperature and leave it alone! :mad::D
     
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  14. Tideland Prius

    Tideland Prius Moderator of the North
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    I had the opposite experience. I had people riding in my car during the winter see the A/C light illuminated and turn it off for me (probably thought I left it on by mistake and I know they mean well so I usually just smile or otherwise acknowledge their gesture). Car features aren't explained well when people pick up the car (or if people by 2nd hand vehicles) and as a "product advisor", you can't assume everyone knows how automatic climate control works. I have friends who have new cars and still don't own a car with automatic climate control. Some know how it works, others don't.

    [​IMG]
     
  15. Mendel Leisk

    Mendel Leisk Senior Member

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    That's a scary picture. :eek:
     
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  16. jonb505

    jonb505 Member

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    Judging by that Picture I'm 99% certain you live somewhere between Edmonton and Winnipeg. :D
     
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  17. kithmo

    kithmo Couch Potato

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    Must be an Ice road trucker on his way to work :)
     
  18. Mendel Leisk

    Mendel Leisk Senior Member

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    Digital displays just don't impart the proper impact. A needle gauge would be better, kinda bending at the lower stop, in the icy blue zone.
     
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  19. Tideland Prius

    Tideland Prius Moderator of the North
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    The owner's manual says the display works down to -30°C. That reads -40°C (and where I was, it was -46.1°C that morning. It was probably close to that by the time I took the photo, around 8am.)
     
  20. Tideland Prius

    Tideland Prius Moderator of the North
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    It bottomed out at -46.1°C earlier that morning (photo was taken around 8am). It was probably still -45 or -44 at the time of the photo.

    Here's the rest of the thread that I created to document the Prius' performance in the extreme cold.

    Extreme Cold Weather Performance | PriusChat
     
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