Three-star hotel has 8 floors, but the bathroom exhaust duct was not designed before renovation. Now it is necessary to design the bathroom exhaust. There are 3 rooms with 127 rooms, and how many time

Three-star hotel has 8 floors, but the bathroom exhaust duct was not designed before renovation. Now it is necessary to design the bathroom exhaust. There are 3 rooms with 127 rooms, and how many times do you need to take air? It is suggested to install an exhaust fan in each bathroom, use 11#PVC pipe as the main pipe of each unit, and use 15#PVC pipe as the outdoor main pipe to add rain showers to the 23rd floor, and set movable shutters in branches to prevent gas from flowing back. This saves the use cost. And if it's a bathroom near the outer wall, you can also use the 11 exhaust fan to exhaust directly.