The Fresh Air Inlet (FAI) is where the venting system starts as it draws the colder air into the system and allows it to vent through the vent terminal
Provide air flow to or from drainage system and to protect trap seals from siphonage and backpressure.
A auto vent
Without the help of plumbing vents, water and waste would not move properly through the pipes in your home. They introduce air into the plumbing system so there is no vacuum, and they carry out sewer gases which could potentially make you sick.
To vent off odors emanating from the septic/sewer system and to allow the toilet to flush correctly and the other drains to empty correctly.
I don't quite get what you mean. -A vent pipe in a plumbing system is usually 1 1/2 inch ABS pipe and may extend through the roof, or may end in a AAV under a countertop.
Yes BUT not an outside wall
Yes. The roof vent is usally located on the roof. If the vent is clogged, it can create numerous issues and prevent your plumbing system from working properly.
Vent - Cold Water Supply - Drainage - hot water supply /return
yes,
Vent through roof
You should not have to clean a vent on the roof. unless you are trying to clean the waste line to the fixture below. Then you would send plumbing rods through the vent on the roof.