[honestcharlie56]

I don't know who instructed you that mold growth will magically appear when cutting at the diffuser.....but I've never seen it...and I'm in Houston too! Cutting at the spin in to the main trunk will also yield less leakage than cutting at the diffuser (your building static in less duct work). Last but not least, cutting at the diffuser is noisey. Exactly what type of system is this?