I found some really good information on the hoop style greenhouse that I want to build for my back yard. The door design is the best that I've found so far during my internet searches. The fan location is a nice addition as well although I think I'd slightly modify the design to have fans above the doors at each end with vents that close to allow for maximum air circulation and ventilation.
There are tons more ideas and styles of greenhouses in this book so if you like it click the link above and buy the book to support the author!
