If that is your coop in Avatar,,, I see that you have the ventilation properly located at top. You may not encounter drafts, from the small pop door open into run area. You must also understand the difference between drafts, and air movement. Drafts ruffle the chickens' feathers. Air...
You could screw the nipples into a hose, BUT there are other issues the may arise. A pvc pipe is rigid and the nipples will stay in the position placed. Horizontal, or vertical, as chosen. A hose will not be as stable to keep nipples at desired position. Meaning the hose can twist.
WISHING...