Not the OP, but it can be a difficult conversation.
I had a similar one when I was at CS school, one of our dorm room-mates was always covering the room's window with paper and stuff like that in order to not let the morning sun in. It drove me crazy. Being younger and more impulsive of course that I told him that what he was doing was bothering me. Not sure what the end-result was (this happened ~15 years ago), only that it created a tense atmosphere between me and said room-mate for the remaining of the school year. I'd imagine bringing that additional stress into an work-like environment it's not for the best.