The air in my attic gets superheated during summer, from the sun baking the (clay? terracotta?) roof tiles (I live in Sydney, Australia).
I have good ceiling insulation, and even put in some sarking (foil insulation just under the tiles) but some of the heat still penetrates into the house.
Also, we now have a ducted (central) AC unit in the attic which absorbs a bit of the heat and so cools a bit less effectively.
So I need to cool the attic (area about 100m2). I have 2 vents under the eaves (opposite sides of the house) and one small whirlybird (wind/convection powered thermal chimney).
Should I get more whirlybirds? They are about $100 each and I'm concerned they might not move enough air.
Has anyone used a solar or mains powered roof extracter fan? Can I get one for less than $300 or so?
How about heat-reflective roof paints, are they effective and cheap? (My roof is black and the house will lose a lot of resale value with a light colour)
Any other good solutions?