Recovers 9% every 5 minutes regularly . When you evict a dorm member you reduce ANY dorm mate you put in there to zero. So you need to wait an hour to before you are full, alike if you had absolutely no health at the start of that. Hope this helps
Whenever you evict a dorm mate, unload all your health. Either way you will not be full for an hour. But simple upgrade, shouldn't matter.