Do they have a window to let some light in?
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Hello and welcome to BYC!Glad you joined.
The run they are in looks a lot bigger than 4x5. Your coop looks to be lacking in ventilation though.
I agree with @DobieLover. Do you have any windows or vents in your coop? Remember one thing, when you free range most likely sooner or later your birds will be discovered by predators and when you least expect it they will kill a bird. A gal recently was saying how she free ranges daily supervising the birds and had no issues with predators but the other day had to go into the house to use the bathroom and that is when the predator attacked her flock. Most people who free range will loose a bird sooner or later. Good luck with your new flock and have fun...