An air brick? What the hell? I don’t imagine that a brick composed solely of air would support much weight or provide much insulation or privacy. Maybe I should look at the definition of this term, because I’m guessing I have something wrong.
I was right about being wrong. An air brick is a brick that has perforations to allow ventilation.
I don’t know what applications air bricks serve. I live in Canada. We get winters here. I don’t imagine too many homes here are built with air bricks. We generally go out of our way to keep the outside air out during winter. We don’t invite it to flow freely into our homes.