What is a wind turbine roof vent?  A wind turbine roof vent is generically known in Australia as a whirlybird.  How do they work?  Well, the theory is that with one whirly bird you will need 4 eaves vents for the whirlybird to allow air to enter and exit through the whirlygig.

However, the fact is that most whirlygigs don’t have any eaves vents at all to allow air to enter the roofspace, say one whirligig out of twenty installed in roofs around Australia will actually have any eaves vents at all.  So what if they do have eaves vents installed do they work then?  No, not really.

Not if you believe Deacon University’s state of the art infra-red technology, even with open eaves they proved to not work to remove any heat from the roofspace in houses they tested – check Case Studies & Reports on this website “Whirly Birds Don’t Work”.

So what do they really do, they certainly spin around, however not much else.  So whether you spend $50 or $280 it won’t make any difference other than the placebo effect – you have just wasted your money and made your house look like a factory.

Many years back, or should I say decades before I knew the difference I supplied and fixed whirlybirds for customers.  However it did not take me long to work out that they did not work, rather than exhaust any heat from the roofspace with the spinning I believe they sealed themselves off.

To give you some examples on 30° days I have felt absolutely no heat exhausting from any whirlybird, even in my 50 years as a roofer.  I have been inside roofs with my hand inside whirlygigs feeling no air movement at all.

However the best example I could give you was once inside a warehouse in a country area were 3 big whirlygigs full of spider webs, there was no movement with the spider webs and we all know how light spider webs are.  So needless to say I stopped fixing these things in customers houses.  If asked to fix a whirligig that a customer had brought from a hardware supermarket I would tell them I don’t believe they work and don’t waste your money getting someone to install it.  Best thing to do is see if you can get a credit or your money back.

You will see illustrations of inlet air entering the roofspace from the eaves and the ceiling space, neither happens and the last thing you need is holes in your ceiling.  These openings in the ceiling allow the nasties of the roofspace to enter the home, there are many blogs on this site to demonstrate the pitfalls of openings in the ceiling.