I’ll give you some background that may help.
This was a new development in Los Angeles in a large area never before built upon (there aren’t many such areas in LA), not far from LAX.
These “vents” were placed about 100 feet apart on the rear fence lines of the properties. They terminate about 10 feet above finished grade. Any guess as to what they are for?
I’ll post additional pictures later on that will answer the question for you.