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Solar ventilation mod

Discussion in 'Gen 2 Prius Main Forum' started by paxbritannica1805, May 11, 2009.

  1. paxbritannica1805

    paxbritannica1805 New Member

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    Hello everyone,
    This is first post although I've had my Prius since Oct 08. I have an idea and was surprised that I could not find any prevoius posts here (or anywhere else for any car).

    It doesnt seem like it would be terribly difficult or expensive to make a solar ventilation system for a 2004-09 Prius. That "flap" (i dont know its proper name) in the rear quarter panel that relieves air pressure when you shut the door and also serves as exhaust for when the AC/heat is on outside air appears to be a good place to place a fan, but will air flow in from elsewhere?? Any ideas?

    It looks like there is enough room for an adapter to pipe the flap opening down to say, an 80mm opening to mount a fan without removing or cutting that little storage compartment on the left side of the hatchback floor. I don't know how I would make such such an adapter yet, maybe try to find a company that makes oddball plastic things based on dimensions you provide.

    If that can be worked out, it seems straightfoward...

    Place a flexable PV panel on the roof similiar to these..
    5 watt.. $100

    10 watt.. $200


    connect it to a fan.
    I have a very powerful 80mm CPU fan. I measured a 0.7 amp draw at 12V ... 8.5 Watts, but of course it will spin with much less power.

    I cant post links yet :(
     
    #1 paxbritannica1805, May 11, 2009
  2. Matt Herring

    Matt Herring New Member

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    If you go to ecomodder.com and pose your question there those guys do many, many mods to their cars (including solar)...they can definitely help you out.
     
    #2 Matt Herring, May 11, 2009
  3. abq sfr

    abq sfr New Member

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    I've thought about doing something like that, think I've seen blowers that you place at the top of an almost rolled up window, you could run those off solar panels. Depending on how much air they discharge they might work but that sun is a continuous heat load. After thinking about the subject a little while I figure it works a whole lot better to park under a tree if you can find one... sure increases my mpg when I can find a tree. Guess you can call me a tree hugger.
     
    #3 abq sfr, May 12, 2009
  4. richard schumacher

    richard schumacher shortbus driver

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    Do those top-of-the-window ventilators include a filter? I'd wouldn't have one blowing dirt into the car all day.
     
    #4 richard schumacher, May 12, 2009
  5. abq sfr

    abq sfr New Member

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    Not the ones I've seen. In addition, reviews indicate they have no effect, probably because the heat load is simply too great for the small devices to overcome. Just open your window for a minute after you start up. Google window car ventilator. It helps a little to crack all the windows half an inch if there's a breeze when no tree is around to park under.
     
    #5 abq sfr, May 12, 2009
  6. ChapmanF

    ChapmanF Senior Member

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    If you set up a ventilator to blow out, then the replacement air would probably be coming in through the cabin filter. Unless the damper servos close the fresh air intake when the car is off - I don't know, worth checking.

    Somewhere, Hobbit has written up a circuit for running the built in HVAC blower at low power; that blower's already there, and you could just use PV to feed the existing 12v system (with some sort of precaution to stop the blower drawing more than you're getting).

    The practicality question would be, what airflow rate would be needed to make a meaningful difference in the hot sun, how much fan power is needed to do that, and how much PV area is needed to get that much?

    -Chap
     
    #6 ChapmanF, May 12, 2009
  7. HTMLSpinnr

    HTMLSpinnr Super Moderator
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    The challenge I see is getting a PV panel mounted somewhere where it will function. The IR/UV filtering glass filters out most of the useful spectrum for PV panels.

    We tried one of those "window gap" blowers in our 2002 and while it functioned wonderfully in open air, it all but ceased to spin once it was behind solar-tinted glass.

    There may be RF noise concerns while the car is on/running for those who want to tap into the existing blower motor (ala 2010) - make sure your design accounts for this.
     
    #7 HTMLSpinnr, May 12, 2009
  8. paxbritannica1805

    paxbritannica1805 New Member

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    post # 5 so I can post links
     
    #8 paxbritannica1805, May 13, 2009
  9. paxbritannica1805

    paxbritannica1805 New Member

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    Those little window blowers are out of the question for me. When I think about the tiny solar panel to start with and the poor angle that it has to have, it doesnt seem like it could collect enough power to move more than a token amount of air, and im too lazy to put it on the window each time i park.

    I though about using the HVAC blower, seems a good deal more involved, but mainly im afraid that running 12 hours a day would bring it to an early death. I changed a blower on an old accord, which was a pain, and expensive.

    As for putting the cell somewher effective.. could put
    Flexible Solar Panel - PowerFilm 5 Watt
    (preferably w/o the white trim) on the roof next to the antenna



    12V, moves 80 cfm at 0.7 amps (8.5watts). I bet 5 cfm would make a big difference
    [​IMG]


    Theres room under there..but i would take a very strangly shaped piece of plastic to snake from where you see the fan to the exhaust flap opening behind the storage bin.
    [​IMG]

    over an inch is hidden by the trunk lining
    [​IMG]
     
    #9 paxbritannica1805, May 13, 2009
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