Is a 4 x 8 open air coop large enough for 4 standard chickens?

[Happy hen lover]

3 for a short time. Add what you can, as you can. The actual coop looks too small with no ventilation to start with. You should focus there. Or add some wind block and skirting to the run and let them sleep there..the coop can be for nesting.

I agree make that your coop and add a run that's 40 SQ feet for 4 hens. Coop should be 3-5 SQ foot per hen. Roost 1 foot per hen.