I have 2 chicken doors out to 2 separate runs, on the front of the south side, and the right of the east side. I was planning on just leaving open the one on the east (back) b/c we have trees the block the worst of the wind & hopefully snow and figured that'd be enough ventilation, and they could go outside if the wanted. There's a window on the north wall I was planning on closing unless we get an unusually warm day (we had freak 70-80 degree weather last Feb) and the human door has a window, but I was planning on closing it up for winter b/c it faces where the snow comes from (west) & it gets very windy. I don't have any insulation on the walls, it's just plywood. I understand that ventilation is important, but how do you let in air w/o letting in wind and snow? I know chickens generally like it cooler, but at what point should I worry that it's getting too cold for them? I'd rather not find out the hard way accidentally kill them.