You’re right about the main door, it’s facing wall, I chose to place it that way as I felt it more important to utilise the top vent and duct it into our heat transfer ducting. I’m diagnosed personality disordered anxious avoidant (that’s two axis II traits), also complex PTSD, panic disorder and major depressive disorder, anxiety disorder. So it was more important to me that I disperse the heat through the house to avoid FLIR detection. Quite handy to have proper ducting to attach to, I used a jubilee hose clamp tightened at end of ducting then four cable ties off the clamp attached to vent. I wanted to keep it short and straight for optimum extraction I’m lucky I’m physically fit and able so a small door isn’t a problem.