Ventilation is not bad. The picture has a vent on both sides with a cover. The back vent is closed in the picture. There are also gable vents.Wow, check out this article! https://www.backyardchickens.com/articles/timms-medium-coop.65952/
Looks like it needs more ventilation, but this is the kind of "how to" that's super helpful!
For my place it would not have enough vents but it gets over 100 here for 20 or so days each summer