Powered roof vent: some leakage normal?
 

My condo has a powered roof vent on the roof. During heavy rain, if I go
into the attic, I sometimes I can see a mist coming from the opening, and
there is some occasional dripping. What I think is happening is that,
during heavy rain, water can splatter and cause a mist. The splattering
water can also cause water drops to get onto the underside of the hood and
eventually drip through the opening. I notice that someone put an extra
peace of insulation upside down on the attic floor. Presumably they did
that to absorb the occasional drops of water during heavy rain.

Is what I'm describing a normal condition for powered roof vents?

Also I'm wondering what the lifespan of the aluminum vent is (not including
the motor, which was recently replaced).

Thanks,

J.