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Gen 4 HVAC usage and settings?

Discussion in 'Gen 4 Prius Technical Discussion' started by Blizzard_Persona, Aug 20, 2016.

  1. Mendel Leisk

    Mendel Leisk Senior Member

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    I've watched Compressor watts (or amps? Whatever) with ScanGuage, and seen values other than zero with the mode set to Heat/Defog, and the AC button off. A variety of values, say 150, then 300, then back to zero for a while. And sometimes it stays on zero. Depending on ambient temp? And I think the car can also detect humidity level, not sure though.
     
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  2. RCO

    RCO Senior Member

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    Let me get this straight. Does this mean that if the temp inside the car is above or below 73F (24.7C), the ice will come on to adjust to that setpoint? That's good to know. Kudos to HVAC and Alan. (y)(y)
     
  3. alanclarkeau

    alanclarkeau Senior Member

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    I'm yet to test it - I think it converts to 22.7, and it was too warm today. But I had worked out that there was some point where you could either delay the ICE - or force it to run.
    It could well work different in Australia, many PRIUS things work differently down here:
    upload_2016-10-4_19-58-12.jpeg
     
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  4. RCO

    RCO Senior Member

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    Only problem for me is that I'd be happy with 22.7C here in UK but my better half prefers a cooler 17C. There are no prizes for guessing the usual outcome! :cry:
     
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  5. HVAC

    HVAC Member

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    I have read somewhere that it senses the need for dehumidification and was not sure if AC button off would prevent it. Sounds like you answered that. The scan gauge sounds like a great tool. Were you able to see if the PTC electric heaters are on or not ever and easily tell what devices were using power?
    I looked and he was in Banner Elk for a Lees- McRae sponsored MTB race when he was in college. I like what you done with your Prius. How often do you use your block heater. I read Mendel uses yearound mostly.
     
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  6. Mendel Leisk

    Mendel Leisk Senior Member

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    One thing I've observed on 3rd gen: if I'm at a stop in cool weather, the engine has shut down, and the vent system is on with temp set fairly low, say around 20C, if I raise the set temperature, the engine will go on. The threshold is somewhere around 21.5C
    No. Didn't even know what that was; had to look it up. Besides the built-in "gauges" in ScanGuageII, there's extra XGauges which can be programed in. I had a look in a spreadsheet I've found for XGauges (I believe it's linked on Priuschat, a bit fuzzy on that), don't see PTC. I'll attach the spreadsheet.
     

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  7. HVAC

    HVAC Member

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    Thanks for the Kudos.
    I think yours would be the same.
    I will clarify.

    At power up
    Cabin cooler than temperature setpoint
    ICE immediately starts to warm the water for heating the cabin.
    Also some models have PTC electric resistance heaters to give some immediate heat and defrost. There will be fuses for that if you have it.
    I think all Canadian models have them in Gen 4 anyway. Mine does also.

    At power up
    Cabin warmer than the setpoint the compressor can run if AC button on and the ICE will not start for that alone.
    Battery charge, speed, heater demand, then engine warm up initiated and runs to heat the catalytic converter.

    AC alone will not start the engine but heat demand will.
     
    #47 HVAC, Oct 4, 2016
    Last edited: Oct 4, 2016
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  8. HVAC

    HVAC Member

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    I don't see the PTC heater called out either. Thanks for sharing that information. Amazing what is viewable.
    It is possible the PTC power is included in the AC line.
     
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  9. kithmo

    kithmo Couch Potato

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    On hot days I remote roll down all the windows as I approach the car to let out the 40C heat that's accumulated, then the AC has less work to do. In the car I usually have the temp set at 19C and system on AUTO and turn driver preference off for full cabin cooling. On cool days I turn off the climate control (unless I need a demist) and use the seat heater. On very cold days I use climate on AUTO with driver preference on, temp at 21C, with a 5-10 minute blast from the demist to start if necessary. I find these are the most comfortable settings for hot days and the most economical without being uncomfortable on cool or colder days.
     
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  10. RCO

    RCO Senior Member

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    Ah, the vagaries of an English week! :love::LOL:
     
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