Gotta agree with aart. You appear to have no real ventilation. Those 4 little holes don't really count as much.
For example, my coop is 6' by 8'. There are 2 1' by 3' vents under the eaves. Then there is a 2' by 2' vent in the clean out door. The coop is built into the corner of an L shaped house so no wind blows in that vent in the door as it is only a few feet away from the house. There is also the pop door that is open year round. That gives me 11 square feet of ventilation.
For example, my coop is 6' by 8'. There are 2 1' by 3' vents under the eaves. Then there is a 2' by 2' vent in the clean out door. The coop is built into the corner of an L shaped house so no wind blows in that vent in the door as it is only a few feet away from the house. There is also the pop door that is open year round. That gives me 11 square feet of ventilation.