hey all i need some help about ventilation. I just bought a metal 10X16 lofted yard barn. It has no vents but it does have two windows. Im dividing the building into two sections, the front half is for storange and what not and the back half is for my 7 hens. The two windows are centerd in the back half for the girls. Now my question is what kind of vents can i make or buy to vent it? Ive looked all over the coop section to see how other did theres but didnt have much luck. Any help would be great.