Our New TT (May-2020) has a Electric/Propane water heater that has become very noisy lately. If only it were not right next to the bed. But it is and the 2' proximity with a very thin wall for seperat...
Yes, those are open at least 2/3s, but I think Old-Biscuit is just using the picture to show what slots, rather than suggesting the pictured setting is 1/4. He is a good source of reliable information!