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Thread: Breeze Panel Update

  1. #1
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    Default Breeze Panel Update

    Last year, someone posted about villagers in some hot place using old soda bottles to fabricate breeze panels to help ventilate their homes.

    By facing the large openings to the breeze, it increases the air velocity coming from the small ends, increasing the airflow. I thought it was interesting and did a quick mock-up (at bottom) for a test in my greenhouse.



    While the effect was noticeable, it really didn't move all that much air. So I thought about it and built an improved version (above), using jugs with a square cross-section to capture airflow over the entire surface.



    Used a hole-saw on a scrap of polycarbonate and attached the jugs with construction adhesive, then taped the cut edges together with clear packing tape.



    This one actually works pretty well for pushing cool air. Maybe not so good where there are lots of mosquitoes.

    We're merely mammals. Let's misbehave! óCole Porter

  2. #2
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    Default Re: Breeze Panel Update

    I'm thinking overall you are going to get less air. Maybe close up the increased velocity feels cool on your hand or face due to an enhanced evaporative effect, but go back a foot or two end even that will be lost won't it?

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    Default Re: Breeze Panel Update

    Quote Originally Posted by Phil Y View Post
    I'm thinking overall you are going to get less air. Maybe close up the increased velocity feels cool on your hand or face due to an enhanced evaporative effect, but go back a foot or two end even that will be lost won't it?
    With a light breeze outside, I can feel a strong current of air a meter or more from the panel. A side effect is to create some turbulence and stir the inside air.

    A good test would be to measure at the outlets and see if the airflow through the structure is increased, but given the ventilation setup (three other inlet vents and four exit vents), there's no practical means to do that.
    We're merely mammals. Let's misbehave! óCole Porter

  4. #4
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    Default Re: Breeze Panel Update

    Interesting. Some pop rivets with a washer to connect the bottles might increase longevity over the tape.

  5. #5
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    Default Re: Breeze Panel Update

    +1, increased resistance = les air flow (total)
    Quote Originally Posted by Phil Y View Post
    I'm thinking overall you are going to get less air. Maybe close up the increased velocity feels cool on your hand or face due to an enhanced evaporative effect, but go back a foot or two end even that will be lost won't it?

  6. #6
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    Default Re: Breeze Panel Update

    At least it'll keep out most of any birds and rain.

  7. #7
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    Default Re: Breeze Panel Update

    Is it the right way around?

  8. #8
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    Default Re: Breeze Panel Update

    I thought the idea was high pressure to low pressure, therefore cooling the air?

  9. #9
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    Default Re: Breeze Panel Update

    At first glance I thought it must reduce flow because of the restrictions. It should increase speed, it also my move the "intake" away from the flat surface, reaching into moving air that would otherwise go around. I'm not an engineer, so just thinking of inlets and air flow around objects as observed while sailing.

  10. #10
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    Default Re: Breeze Panel Update

    'm thinking overall you are going to get less air. Maybe close up the increased velocity feels cool on your hand or face
    Well, on a hot day, placing a chair by the window and feeling cool is a decent substitute for a good breeze or AC, no?

    Surely not for environments where bugs thrive.

    Kevin
    There are two kinds of boaters: those who have run aground, and those who lie about it.

  11. #11
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    Default Re: Breeze Panel Update

    I don't think those bottles stick out far enough to leave the stagnation zone.

    Screen would keep the bugs out, but it is remarkable how much airflow resistance bug screen produces.

    The best test would be to track greenhouse temperature. See if it is cooler with the bottle panel, or with just an open panel. You might have to track it over several days, alternating to average for different weather.

  12. #12
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    Default Re: Breeze Panel Update

    Quote Originally Posted by robm View Post
    The best test would be to track greenhouse temperature. See if it is cooler with the bottle panel, or with just an open panel. You might have to track it over several days, alternating to average for different weather.
    Stagnation zone (or boundary layer) isn't an issue, because the idea is to place the panel on the side that gets the prevailing breeze.

    Measuring the effect on temperature is a bit complex because the greenhouse has three inlet vents (besides the window opening in the door) and four outlet vents in the roof. The passive ventilation for the greenhouse depends on the outdoor air temp being considerably lower than the temp inside.

    The best way to measure would probably be to get a cardboard carton the same size as the breeze panel. First, measure the internal temperature in full sun with both ends closed. Second, measure the temp with both ends open. Third, insert the breeze panel with the other end open. I have a wee digital thermohygrometer I used for testing tents, which I used to review.

    I copied the initial post to my greenhouse thread, if that might be of interest:

    http://forum.woodenboat.com/showthre...e29&highlight=
    We're merely mammals. Let's misbehave! óCole Porter

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