I'm working on a bathroom remodel and have had to reloacate a vanity drain. When I opened up the walls, I found I will have to relocate the copper water lines for the vanity and tub/shower. There are all kinds of fittings to make the complicated bends that the builder made to get the copper through the wall and around the corner to the tub and shower. The copper comes up through the bottom of the wall and T's off to the vanity and then T's off to the shower/tub. The lines continue up to air chambers. If I cut off the copper near the floor and transition to PEX to more cleanly navigate my walls, do I need to go back with an air chamber and if so, what would the best way to accomplish this be?