I have a high peak greenhouse with two roof vents that open with paraffin vent openers. You can see one of them open in the upper right side of this pic. I also have a couple of fans to keep the air moving. To get better air flow, circulation and venting, I am thinking of putting in a louvered exhaust fan with thermostat high up on the peaked wall and a motorized intake louver low down on the north wall. If I do this, do I really need the roof vents...I guess I am thinking more for the cooler/colder weather. The paraffin controlled vents are slow to react, and I don't want to lose all my heat. I'm thinking of sealing them for the winter and dropping the ceiling somewhat using bubble wrap to preserve as much warmth as possible. Any thoughts?