If you are going to have vents on opposite walls, and live somewhere that gets real winter, you'd better be sure you have ENOUGH on JUST the downwind wall to get by with the upwind one shut, which is how you'll spend most of the winter.
If you're only going to have vents on 2 walls, adjacent walls are probably best. I'm talking cold-weather ventilation here -- in hot weather, what matters is not so much where they're located (although open to the prevailing breeze helps) as just having *a lot*.
Hatrick, I can suggest a two options to consider:
- you could add another vent on the E side to make sure you have enough, or possibly on the E end of the S side of the coop. BTW, although your vent is not overly large (possibly ok for just 3 chickens tho) that is a
great hood for it, what is that, a dryer vent hood?
- you could cover and plasticwrap the run, except for the E-facing part that's not against the coop and possibly also excepting the S side facing the fence. This will go a long ways towards keeping the wind from whooshing directly in thru the popdoor during the day. The popdoor will be closed at night, so cross-drafts should not be an issue then.
This is not either/or; you could certainly do both.
Don't put a vent on the N side when you live in the N, you will not be able to use it most of the winter
lamelde, you will certainly be in good shape if you provide 1 sq ft of total vent space per chicken, or 1 sq ft per 10 sq ft of floorspace in the coop. A number of coops can get away with less, but not all, so the most guaranteed thing is to just build *lots* of adjustable/closeable ventilation and then you will be pretty sure to have enough no matter what
Good luck, have fun,
Pat