It is very important to point the elbow downwind when installing the toilet exhaust pipe on the roof. The purpose of this is to ensure that the gas can be discharged smoothly and prevent the gas from flowing back. When the toilet is used, the polluted gas is discharged to the outside through the exhaust pipe. If the elbow mouth faces the upwind direction, the gas cannot be discharged smoothly, and even flows back to the room, causing odor and hygiene problems. Facing the bend in the downwind direction can effectively promote the downward flow of gas and avoid backflow. When installing the toilet exhaust pipe, you also need to consider the local climate conditions and wind direction changes. The climate and wind direction in different areas may affect the emission and diffusion of gases. When choosing the installation location, the best installation direction and angle should be determined according to the local climate characteristics and wind direction, so as to ensure that the exhaust pipe can play its greatest role, effectively remove polluted gases and keep the indoor air fresh and hygienic.