If you really want to know if you have a leak (or three) in your RV, perform a pressurized leak test. The pressurized air inside the interior will exit the outside even through the smallest holes (AKA, loose caulking, screw holes, under trim edges, etc).
Seal Tech is one franchise that performs the test. I DIY it with a furnace squirrel cage through a window. I even made my own DIY manometer to check the pressure. The details are in this
thread. Scroll down to the bottom of the page for the test.
You can also DIY with a flooring fan, a leaf blower, or anything else that moves a lot of air. It was also mentioned on this Forum that a member used his Fantastic vent fans to do one. Difficult to believe he had enough pressure but I wasn't there.
