I do not know what the facts of polar doors are but I do know I've had snow drift over my door and I'd have never gotten out if the door opened outward -- just was mighty glad I'd brought the shovel indoors.I think I'm right in saying that exterior doors, even of domestic buildings, in a lot of colder, near polar countries open outward. Simply because the harder the wind blows the tighter the seal around the door becomes. A loose fitting door is blown shut rather than open - thus reducing drafts.