Those are the louvers for a whole house fan. While they're not common in Minnesota, I see a few of them every year while doing home inspections. A traditional whole house fan basically consists of a ...

Q: I thought about installing a whole-house fan so I can run my air conditioner less. The prices and sizes vary quite a lot. How do I pick the best one for my home and will one really save much ...

How do you select and install a whole-house fan? -- W.R., Tulsa. The U.S. Energy Department's Office of Energy Efficiency and Renewable Energy -- http://www.eere ...