What works good to seal AC unit & ducts?

Question

the back side of the unit where the ducts go into 2 rooms was off - I was cooling the attic! This has happened before, anyone know how to seal it better? We've done foil tape & duct tape. niether stay on & now the unit is soaked, so nothing is sticking to seal it.

Answer 1

Large 4-5 ft zip tie wraps that are tightened snug.This is done to the inside part of the duct not the outside(vapor barrier)portion.

Answer 2

If you have metal ducts, get some small diameter 1/2 inch self tapping metal screws and a small drill bit (smaller than the thickness of the s***w), realign the duct and the boot (part that fits in the wall), drill pilot holes through both the boot and the duct and use screws to secure.  

Answer 3

Turn off the system and let the surface warm up, use spray glue before the tape. Then after you tape it up put mastic on all joints to keep them from coming apart, once you use the mastic the ducts will never come apart!