Why do vents default to outside air?

Discussion in 'General Motoring' started by Jeff, Sep 22, 2004.

  1. Jeff

    Jeff Guest

    Just wondering--whenever I use the AC, my Accord keeps defaulting to
    outside air (as do most newer vehicles, I've noticed). I drive mostly
    in traffic and don't like to breathe exhaust fumes filling the car, so
    I'm continually resetting it to recirc. But I'm curious as to why
    outside air is the default setting. (?)

    2000 Accord v6 sedan

    Jeff
     
    Jeff, Sep 22, 2004
    #1
  2. Jeff

    Sparky Guest

    Honda flipped a coin, maybe?
     
    Sparky, Sep 22, 2004
    #2
  3. Jeff

    Sparky Guest

    Honda flipped a coin, maybe?
     
    Sparky, Sep 22, 2004
    #3
  4. Jeff

    rjdriver Guest


    Probably the same reason many other car manufactures do, so that can
    have that ridiculouly labelled "Max Air" button, which merely changes the
    air flow from outside to recirculate, and makes people think they have two
    levels of air conditioning power.


    Bob
     
    rjdriver, Sep 22, 2004
    #4
  5. Jeff

    rjdriver Guest


    Probably the same reason many other car manufactures do, so that can
    have that ridiculouly labelled "Max Air" button, which merely changes the
    air flow from outside to recirculate, and makes people think they have two
    levels of air conditioning power.


    Bob
     
    rjdriver, Sep 22, 2004
    #5
  6. Jeff

    E. Meyer Guest

    The AC uses a "just enough and no more" sort of logic. When it decides it
    can't achieve the temperature you asked it for, then it opens the recirc
    door. If you have the AC where you select a temperature, set it to 60
    degrees (F) and the recirc light will come on immediately (unless the
    outside temperature is 40).

    You should know that even when you put it in recirc, a small amount of
    outside air is still drawn in. This is so you don't pass out from your own
    exhaust fumes concentrating in the car.
     
    E. Meyer, Sep 22, 2004
    #6
  7. Jeff

    E. Meyer Guest

    The AC uses a "just enough and no more" sort of logic. When it decides it
    can't achieve the temperature you asked it for, then it opens the recirc
    door. If you have the AC where you select a temperature, set it to 60
    degrees (F) and the recirc light will come on immediately (unless the
    outside temperature is 40).

    You should know that even when you put it in recirc, a small amount of
    outside air is still drawn in. This is so you don't pass out from your own
    exhaust fumes concentrating in the car.
     
    E. Meyer, Sep 22, 2004
    #7
  8. Jeff

    Brian Smith Guest

    That's interesting. Perhaps you should have your vehicle's system checked
    for a problem. My A/C does nothing, unless I tell (push a button) it to
    perform a task.


    --
    Brian

    http://www.cakesbydarlene.ca

    http://www.accesswave.ca/~orion
     
    Brian Smith, Sep 22, 2004
    #8
  9. Jeff

    Brian Smith Guest

    That's interesting. Perhaps you should have your vehicle's system checked
    for a problem. My A/C does nothing, unless I tell (push a button) it to
    perform a task.


    --
    Brian

    http://www.cakesbydarlene.ca

    http://www.accesswave.ca/~orion
     
    Brian Smith, Sep 22, 2004
    #9
  10. I have 99 Accord, European Model With Automatic AC, when I use it on
    Full AUTO , the outside Air vent is closed, which make sense, on
    Manual I presume every setting should me manual.
    Few months back I was in LA , where I drive Toyota Camry , in which
    outside air vent was independent of using AC
     
    George Kinley, Sep 22, 2004
    #10
  11. I have 99 Accord, European Model With Automatic AC, when I use it on
    Full AUTO , the outside Air vent is closed, which make sense, on
    Manual I presume every setting should me manual.
    Few months back I was in LA , where I drive Toyota Camry , in which
    outside air vent was independent of using AC
     
    George Kinley, Sep 22, 2004
    #11
  12. Jeff

    ravelation Guest

    I think the OP is talking about auto climate control. The system
    utilizes recirc for fast cooling and when it's achieved, changes to
    fresh air.
     
    ravelation, Sep 22, 2004
    #12
  13. Jeff

    Rob Guest

    Because once the inside air has been dehumidified through the process
    of a/c, the a/c will struggle to cool that air again.

    recirc works great to cool a steamy car initially, because it is not
    only throwing cold air at you, but is taking away the hot inside air.
    but once the car has cooled you want to switch back to outside air
    (unless a situation like behind a bus, etc., as you mention).

    also windshield will fog up in certain conditions when using recirc.

    rob
     
    Rob, Sep 22, 2004
    #13
  14. Jeff

    Rob Guest

    Because once the inside air has been dehumidified through the process
    of a/c, the a/c will struggle to cool that air again.

    recirc works great to cool a steamy car initially, because it is not
    only throwing cold air at you, but is taking away the hot inside air.
    but once the car has cooled you want to switch back to outside air
    (unless a situation like behind a bus, etc., as you mention).

    also windshield will fog up in certain conditions when using recirc.

    rob
     
    Rob, Sep 22, 2004
    #14
  15. "Rob" wrote
    This is all backwards to me, unless it's because I live in a hot, dry
    climate. When first getting into the car, the temperature inside the car can
    be 40 degrees hotter than outside; therefore, here one first needs to use
    fresh a/c. Once the interior starts to cool off, *then* switch to
    recirculate. The a/c won't have to work so hard, cooling air that is already
    temperate, not at inferno-grade.
     
    Howard Lester, Sep 22, 2004
    #15
  16. "Rob" wrote
    This is all backwards to me, unless it's because I live in a hot, dry
    climate. When first getting into the car, the temperature inside the car can
    be 40 degrees hotter than outside; therefore, here one first needs to use
    fresh a/c. Once the interior starts to cool off, *then* switch to
    recirculate. The a/c won't have to work so hard, cooling air that is already
    temperate, not at inferno-grade.
     
    Howard Lester, Sep 22, 2004
    #16
  17. Jeff

    MLD Guest

    Might be a function of the climate control temperature setting. Put the
    temperature at minimum (60) and see if the recirc light comes on. I have a
    2000 Accord V6 and that's what happens.
    MLD
     
    MLD, Sep 22, 2004
    #17
  18. Jeff

    MLD Guest

    Might be a function of the climate control temperature setting. Put the
    temperature at minimum (60) and see if the recirc light comes on. I have a
    2000 Accord V6 and that's what happens.
    MLD
     
    MLD, Sep 22, 2004
    #18
  19. Jeff

    Abeness Guest

    Right. Backwards. It's easier to make already cool air colder, or to
    keep it cool--there's less heat to remove to the cooling coils. Also,
    same goes for humidity. If you keep pumping super humid air from outside
    into the car, the air won't necessarily get as dry as it would if you
    use the recirc setting.

    I'd guess it's switching back to outside air for safety reasons--these
    newer cars are so airtight that one needs a fresh supply or air to
    prevent CO poisoning if there were a problem with your exhaust system,
    for example. Or as others have suggested, the climate control could be
    doing it based on air temp.
     
    Abeness, Sep 22, 2004
    #19
  20. Jeff

    Abeness Guest

    Right. Backwards. It's easier to make already cool air colder, or to
    keep it cool--there's less heat to remove to the cooling coils. Also,
    same goes for humidity. If you keep pumping super humid air from outside
    into the car, the air won't necessarily get as dry as it would if you
    use the recirc setting.

    I'd guess it's switching back to outside air for safety reasons--these
    newer cars are so airtight that one needs a fresh supply or air to
    prevent CO poisoning if there were a problem with your exhaust system,
    for example. Or as others have suggested, the climate control could be
    doing it based on air temp.
     
    Abeness, Sep 22, 2004
    #20
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