A shower's hot and cold drawn on the floor plan as home-runs: M.E.P.flow takes the ½″ PEX up the stud bay, through the top plate under nail plates, bends it onto the ceiling joists (no fitting in a turn) and drops it into a home-run manifold set in the stud bay, which the ¾″ cold main and the water heater feed. At 9.5 L/min the ½″ line runs at 1.38 m/s, loses 0.25 bar and leaves 3.25 bar at the shower; hot water arrives in 10.3 s over 10.6 m.