Top comes out on the roof:

Not sure what happens below. Haven’t gone under the house to inspect. Seems like a vent that travels through the wall space, but unclear why it would do that.
Any ideas what its purpose is?
Top comes out on the roof:

Not sure what happens below. Haven’t gone under the house to inspect. Seems like a vent that travels through the wall space, but unclear why it would do that.
Any ideas what its purpose is?
Its also not near the rest of the plumbing, so I don’t think so.
Australia for what its worth, but freezing isnt really an issue here.