I am new to keeping chickens and have read that alot of disease and sickness can be prevented with good hygiene and good ventilation. Can anyone give me some idea of how much ventilation I need in my coop? My Coop is 3ft x 2ft x 3ft with a 'pop hole' 12"x 7". The roof is raised on each corner with a small square of 1"x 1" timber, ineffect creating a 1" gap all the way round the top of the coop between the top of the coop and the roof. This is fronted by Facia as th prevent direct draft, so the air flows onder the facia and into the coop( I hope this is making sense) Is this sufficient or do i need more ventilation? I only have 2 Birds in the coop?