What would happened if I bend ventilation stack through top of wall instead of through the roof. Will the system work or not

What would happend if i bend ventilation stack through top of wall instead of through the roof. Will the system work or not

You will be venting sewer gas inside your house if you don't terminate the vents out the roof. Sewer gas is harmful to your families heath and the methane content makes it explosive. Run all vents outside! Good luck, Tom