whirly birds

huangyhg

"whirly birds"
do "whirly birds" .... the roof mounted attic vents that we see on many roofs actually provide proper ventilation.  i have even seen some that were running backwards.

they are not much better than static vents.  they can also be annoying if they squeak!
good ventilation involves a thermostat/humidistat controlled fan.
thanks for that   i agree.  any idea about reasonable cfm?
depends on the size, but all are low.
ron:
my experience with whirly birds is that they work quite well and the air extraction is very good... much better than static vents.
dik
dik...maybe my experience is anecdotal, but we have had problems with them seizing from corrosion.  have you experienced any of that?  i'm in the se us, near the coast which has some influence, but have seen inland as well.
i think there is a wide range of quality in these things, both in terms of ventilation and corrosion protection.
you might ask this question of the mechanical guys.
i also think some installations do not provide the intake vents needed to allow the "whirley birds" to suck the air out.
that's right, no point in installing vents if there is not enough intake where the air is cooler.
ron:
(sorry, wiping the egg off...) my experience is in ontario (somewhat humid, but no sea air for corrosion) and in manitoba (dry)... i've not experienced corrosion issues, but the galvanising on the moveable parts in minimal.
dik