On Wed, 3 Jan 2018 20:00:00 -0500, Alex wrote:

wrote:
On Tue, 2 Jan 2018 19:50:14 -0500, Alex wrote:

Yup, soffit vents, ridge vents and gable end vents. I can move a lot
of air.

OK, it's mounted in the ceiling. I've seen those. The type I remember
had louvers that were opened by the air flow and closed on their own.
Kind of noisy, as I recall, but very functional.

That is the one.