Whirlybird Roof Ventilation or Similar Solution

Looking to install some whirlybirds or similar for the house, garage (which is external to the house) and shed.

All get hot in summer and need some ventilation. Also, apparently, there are some benefits for the house in the summer.

Obviously for a whirlybird, you need wind/breeze for it to work effectively. I've seen some solar ones available which would kick in whether there is wind or not.

Looking for something that is ideally cost-effective for purchase and self-installation. Colourbond roofing for all 3 structures.

Comments

  • +1

    Get one that is motorised.

    • +1

      Yes, hence the solar option. This one appears to also have a 240v option coming soon.

      • -2

        Solar wont work in the evening when your roof will still be hot inside…

        • Yes, I know. But even a wind one won't work when there is no wind.

          The only option is 100% motorised running 24/7.

          This one has solar and 240v. So best of both worlds. Runs on solar when there is sun, 240v overnight.

        • Only powered fans can achieve a sufficient extraction rate to make any difference. However I gather 10-15 whirlybirds will work ok.

        • the roof doesn't tend to heat up too much without the sun shining on it.

          • +1

            @freefall101: Yet retains the heat throughout the day…

      • The solar one looks interesting, I had no idea motorised vents were a thing!

  • +7

    Your statement that you need wind for them to work correctly is not correct. They only spin to show that they are working. Hot air in your roof space rises and leaves out of the whirly bird. You need to have vents in your eaves for fresh air to enter the roof space to replace the hot air that has just left.

    • You need to have vents in your eaves for fresh air to enter the roof space

      So without vents, your roof space is in a vacuum?

      • +15

        Yes, and if you enter the roof space you might Dyson.

        • +1

          That would suck

          • +1

            @jv: This thread is just alot of hot air.

      • The opposite. The warm air would create a POSITIVE PRESSURE which is the opposite OF A vacuum. Nice try THOUGH.

        • The warm air

          No vents, no air…

      • Would explain why my house, my landlord's house anyway, stays so hot after a hot day. It could be cold outside at night but still hot inside because all the bricks and the inside of the roof is full of hot air that has nowhere to go. If a vent could flush all that hot air out and replace it with cool outside air then the house would be a lot more comfortable.

  • Unless you're on tin roof with no insulation and no roof cavity it's a waste of money in vic. Better spend some decent money put r5 on the roof so you can benefit from it year round.

    • I have solar. I have insulation. I have a roof cavity.

      • Then what roof do you have? Terracotta or cement has plenty of gaps in it making whirly bird a moot point. And when it's 35+ just pump aircon out to clear the hot air hovering under the ceiling, by the time sunset it should not be the problem in vic anyway

        • Then what roof do you have?

          Colourbond roofing for all 3 structures

          And when it's 35+ just pump aircon out to clear the hot air hovering under the ceiling, by the time sunset it should not be the problem in vic anyway

          I am looking for a solution for shed, garage and house. So whilst yes, I could do that for the house, the shed and garage don't have that option.

          • -1

            @geekcohen: Ah yes, that final bit of text at the bottom that I missed. I don't know much about your shed or garage but I'm pretty sure the shed will be a waste of money. The garage if part of a newer built under same roof will be better off with insulation, and cheap.

    • How much $$$ are we talking? I don't think I have sufficient insulation / good insulation, house gets hot pretty quickly. Typical 3br house single story.

      The research I did a whole ago lead me to believe whirlybirds were not a good solution for me. I should talk to my neighbour though, has a nice looking one.

      • Insulation always trumps over some temporary measures like whirlybirds. Probably looking at <$5k, if diy then less than half that.

  • +3

    If you got rooftop solar why don't you install a mains powered extractor fan and set a timer for it to work?

    • +1

      That might have to be the way I end up doing it. I've got solar.

      • +2

        Get an inline fan, get some cheap ducting from Bunnings and vent it out wherever you please.

  • They are clearing out a few of the solar powered models at bunnings, so you might want to check around.

    This was Moorabbin today

    The cheaper one is solar, the more premium one is solar+4-6 lithium batteries to keep the fan going for a few hours after dark.

    They were discounted at another bunnings, so it's probably a statewide thing, although at that one the price was quite a bit higher ($90/$100)

    • Thanks, I will try and take a look. Any change those I/N numbers are a bit clearer on your end? Got them.

      0811064
      0811215

  • We recently got a ducted solar exhaust fan installed by Sunshine Skylights (based in Brisbane). Costed just over $1.1k.

    • Costed just over $1.1k.

      Yeah, not worth it in my opinion. I'd rather go without for that price.

      • Most of that cost would have been labour - so if you're looking to install yourself, should be able to pickup the vents for <$500ea.

        Something like this item from eBay for $450ea. Looks very similar to the unit we got installed, although can't speak to the legitimacy or quality of this particular vendor/item.

  • We have two regular non powered units. Tiled roof, they spin fast on hot days even with no wind and made a decent difference, even before refreshed the insulation the roof.

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