Smoke Coming Through the Bedroom Vent

You rent a flat above a bakery in Dunvale, southwestern Ontario. Your neighbour, Davin, rents the flat beside yours. Several evenings each week, cigarette smoke from his flat enters your bedroom through a shared vent, and you have to leave the room while it clears. Davin has mentioned that he enjoys smoking at home after work. There is a sheltered courtyard downstairs where smoking is permitted, but reaching it means going outside. You have always been friendly with Davin, and he may not realize that the smoke reaches your bedroom. The property manager handles maintenance requests.