Ok i glanced through the thread. Sounds like you got the soffit boards out. Nice work. that will be your air intake. Now you really need a ridge vent to work as your exhaust. Metal roofs are great BUT the inside temp needs to be the same as outside temp or you will get condensation. The ridge vent will allow the air movement to occur. Can you get close up pictures of the ridge vent inside and out? If possible use a closed water system as your waterer.