Solar Star RM1600 Roof Ventilation

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  Protractor on 02/10/2023 - 22:20

  What colour and material is your roof,and is it insulated?

  Re the ceiling vents ,seen these?
  https://www.bradfordventilation.com.au/home-ventilation/roof…

  Externally, go for bushfire proof options where you can, because most will also keep not only embers out, but some creepy crawlies.
  If your eave and other lower inlet capacity well exceeds the roof outlet, you should also get natural air flow outward
  Western sun is a bitch. look at ways to shade that influence if you can.

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  [Deactivated] on 02/10/2023 - 23:30

  @Protractor
  It's a mid grey, flat iron roof with a pitch of only 2 degrees.
  Hence there's no height for the hot air to rise.
  It is insulated with sarking and fibreglass batts which don't do much.
  Surface area is only 145 sqm because it's a two storey house.
  The ceiling vent you linked is exactly what has been specified in the quote. 👍
  The house faces west and has lots of glass.
  The windows are tinted, I have outside awnings and block out blinds.
  Most of the heat upstairs is felt below the ceiling and that is why I am hoping that the solar ventilation will help.
  Unfortunately, there is no opportunity to plant shade trees.
  Thanks for your advice. 👏

  • 

    Protractor on 02/10/2023 - 23:51

    Ugly as it seem when dealing with the scorching western summer sun,, comfort is king. Consider a summer only option of draping shade cloth by whatever design you can live with, to cover that western aspect. There's other more complex /permanent /expensive add ons you can try, but KISS is your friend, if your age and physical ability allows you to put up a sun block model and take it down at summers end.If you go a shade cloth get a 90-100% in a dark colour and space it out more than 70mm from the glass if you can . Wow, 2 degrees, that's a challenge. I presume you have ceiling fans already
    PS avoid whirlys,period
    PPS One powerball or a permanent solution to the overhead summer sun >
    https://architropics.com/double-roof-for-cooler-house/
    Keeping in mind west still needs abating

    • 

      [Deactivated] on 03/10/2023 - 00:12

      Unfortunately shade cloth is not an option nor is building a second roof because I'm on a community title with strict by-laws.
      The owners looked at painting the roof of each house with specialised reflective paint but the cost was considered prohibitive.
      I have ducted RC air conditioning and ceiling fans but they need to operate constantly in summer.
      Hopefully the solar ventilation will reduce my electricity bill. 🤞

      • 

        Protractor on 03/10/2023 - 00:17

        Personally I think the minuscule difference any paint can make would be barely perceptible.
        I also think you need to SERIOUSLY consider renegotiating those crazy bylaws in line with climate reality and cost of living going fwd. The second roof thing was a balls to the wall option.
        Multistory homes are a bitch to climate regulate economically and sustainably,,unfortunately, especially if not designed well initially.
        I think a solar driven fan will be hard pressed to extract enough air quick enough, but let's hear from the current users. Be great to see some before and after inside and out temp levels

        • 

          [Deactivated] on 03/10/2023 - 00:29

          @Protractor: @Protractor
          Thanks 👍

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  FloatingPoint on 03/10/2023 - 10:45

  Are you allowed to put some solar panels up there? Not a cheap option, but it gives you free power to run your air con, and some extra shades to part of the roof.

  • 

    [Deactivated] on 03/10/2023 - 12:01

    One of the neighbours in the community development has installed solar panels albeit they weren't allowed to tilt them.
    I'm not sure what their efficiency is on a flat roof with just 2 degrees pitch 🤔
    However, now that you mention it I recall the neighbours saying that it felt cooler upstairs after the installation of the panels.

    • 

      FloatingPoint on 03/10/2023 - 12:12

      You can get some idea from here.
      https://www.solarquotes.com.au/solar-calculator/

      • 

        [Deactivated] on 03/10/2023 - 13:57

        Oh that's very interesting. It's not recommended to have a tilt of less than 10 degrees and some panels may not be suitable for horizontal mounting 🤔

        • 

          FloatingPoint on 03/10/2023 - 15:47

          @[Deactivated]: You may need to contact an installer for advice. However nobody would have noticed if you tilt them slightly to 5 or 10 degrees. 😉

          • 

            [Deactivated] on 03/10/2023 - 16:30

            @FloatingPoint: 😉

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  lgacb08 on 03/10/2023 - 10:57

  Best bet would be ripping out all the roof sheet and lay proper r6 insulation on it or go the split system path. I doubt you'll get much airflow with this set up and with additional noise issue

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    [Deactivated] on 03/10/2023 - 12:05

    I would love to have R6 insulation but a quick calculation reveals that the batts alone would be around $2,500.
    I'd need to get a quote for installation.
    I do have ducted RC air conditioning so are you saying that a split system would be a cheaper alternative to run?

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      lgacb08 on 03/10/2023 - 20:10

      Yes, a split will be million times better and cheaper to run. Your ducted will be likely have only one intake and temperature on that will not correctly reflect the heat you have upstairs so you always have problems. If you can't afford r6 then r5 will do. If you're complaining about material cost then I can tell you won't be able to afford split because you probably need more than one, each cost at least $1500 supply and install.

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        [Deactivated] on 03/10/2023 - 22:05

        Thanks 👍