Whirlybirds vs Solar Power Roof Ventilators
Today, we will be looking at the arguments for and against solar powered roof ventilators and whirlybirds.
The strongest argument for Whirlybirds is that they are cheap to purchase. However, they also need to be installed. Domestic whirlybirds are generally quite simple to install, but if you can’t do it yourself – the cost of getting them installed by a certified roofing plumber will normally be several times the cost of the whirlybird roof ventilator itself.
Solar roof fans are more expensive, but as mentioned in part 1, they are 10-30 times more effective – so for most homes – you really only need 1 unit for the whole house (unless you have separate roof spaces).
In order to move enough air to make a difference to the temperature in the roof space in average Australian home – at an airflow capacity of approx. 100 cbm/h per unit – anything less than 10 whirlybirds for a house is unlikely to make a noticeable difference to both the roof space temperature and the amount of heat radiating through the ceiling into the house.
If you look at the cost of purchasing 10 whirlybirds (whirlygig) vs one solar powered roof ventilator – the numbers don’t stack up very favorably for the whirlybirds – especially not if you have to pay to install them. The solar powered roof ventilators are far more valuable if you need power and want to make a serious difference to the air flow changes within your house hold or business.