Whirlybirds

[Generalzod]

The worst thing I’ve ever done is install insulation bats on my roof I’ve noticed that my second floor is usually more hotter, just wondering will installing a few whirlybirds make any difference ? Or are they a gimmick.

 

[Mr Angry]

Whirlybirds work, only so much but they expel the hot air.

I only have them in the garden shed/workshop, which is not small, they help alot, not sure about a roof with batts.

 

[Twizzle]

They only work when its windy and cooling your roof space down wont do anything for the habitable rooms. Level 1 in a 2 story house/unit will always be hotter than the ground floor

As to how effective they are can depend on the ambient temperature and wind velocities as if you exhaust hot air from high areas then you replace it with high temperature ambient air and 30 degree air wont cool down a habitable room space

the only way to cool it down it to force cold air in ie; air conditioning

some times air movement can cause the body to cool itself by evaporating moisture from your skin ie; perspiration and to do that you generally need a fan (mechanical ventilation)

most forms of natural ventilation are useless on a day when there is no wind velocity and they are generally the times when you need it to work

 

[muzby]

This really wasn’t the topic I thought it would be when I read the title.


I’ll be going now.

 

[myrrh ken]

The worst thing I’ve ever done is install insulation bats on my roof I’ve noticed that my second floor is usually more hotter, just wondering will installing a few whirlybirds make any difference ? Or are they a gimmick.

Surely the insulation cools things down no? I have no insulation in my roof i don't think. It's hot as f**k

 

[Twizzle]

Surely the insulation cools things down no?

also stops heat from leaking out, so the room stays hot

 

[Willow]

The worst thing I’ve ever done is install insulation bats on my roof I’ve noticed that my second floor is usually more hotter, just wondering will installing a few whirlybirds make any difference ? Or are they a gimmick.

I have them in my work shed and they make a small difference. Not sure how practical they are in a home environment.

Heat rises so it will help a little if it has somewhere to go, plus it helps to expel a lot of fine dust particles which can mean cleaner air depending on the amount of dust.

But on hot days you can't beat aircon.

 

[Zadar]

when the bearings go, they can be noisy as hell and they add another point of water leaks if not installed properly.

we have two, that were on the house when we bought it, not sure if they do much, possibly keeps the roof space well ventilated, but one does make a funny noise when it’s very windy, and I’m not nimble enough to want to jump on the roof to have a look.

 

[GAZF]

Whirly birds need a minimum number of eave/gable vents in the right positions to work effectively. If air isn't moving into the roof space, you can only expect a whirly bird to move so much hot air out of it on account of thermal gradient. The lack of air movement would also be more pronounced in a roof with sarking as gaps are effectively sealed.

One of the best things I've done for the house so far is retrofit sarking under the old (black and unglazed) tile roof in 2019. It dropped the temperature at ceiling height by 5-10°C on a 40°C day. Shit work but materials are cheap as.