I've built a cabinet style incubator using 3/4" plywood. It has a false back with a 8" inline duct fan. I just got a heat coils and insulators. The water shelf is 13 1/2 " as well as bottom shelf. The unit is 3'5" tall 21" wide and 2' deep. The false back is 4".I belive the fan is 210cfm. The door has a sheet of 1/4" plexiglass I do plan to put another over it for better insulation. Right now I have two LG turners in it and plan to use the bottom shelf as the hatching tray. Everything is sealed and polyurethaned. My vents are 1 1/2". One up top behind fan and the other down bottom. I hade it running for weeks empty and couldn't get temp stable so took everything apart and am trying again. So very frustrating but in the end I hope to have some great hatches! If any of you incubator pros out there have any suggestions to get it running I'd love to hear from you.thanks for looking