I'm a newbie at home improvement, so please forgive my initial ignorance when it comes to the technical terms.
I recently contracted with a nation wide vendor to install a central air-conditioning unit in my ranch style home. This nation-wide vendor sub-contacted with a local installer who performed the actual work during May of 2004.
The blower was placed in the attic, with flexible duct work running to the ceiling in various rooms. A large cold-air return was placed in the central hallway ceiling.
During the first year I had several problems with the installation. (These included the blower drain that didn't function properly (causing ceiling damage) and the cooling ducts separating from the vents in the ceiling. These were repaired quickly and without question.
Fast-forward to today. I switch the unit on and realized that the unit wasn't cooling properly. I contacted the nation-wide vendor who dispatched a heating and air specialist to my home. The specialist arrived and proceeded to tell me that the duct work that was attached to the blower unit had "collapsed in-on-itself;" specifically where the flexible duct work met the intake end of the blower unit.
Apparently the original sub-contractor installer used semi-flexible foil faced insulating sheeting to construct a connection from the flexible duct work to the intake end of the blower. This same sub-contractor also created a large box (for lack of a better term) of this same semi-flexible foil faced insulating sheeting and attached it to the ducts with foil tape.
So, my question(s) is this:
Is it typical to connect flexible 6" or 8" ductwork to a blower type unit with 1/2"foil-faced insulation sheeting? In other words, isn't there some type of reducer or pre-fabricated part that performs this function?
Since I have one large central cold-air return, is there any pre-constructed unit that should/could be installed in place of this taped amalgamation? My current setup is a 3' by 3' box that is surface mounted to my ceiling with a 12" flex duct tube going from it to the cold-air intake of the blower.
Is there some type of building code that dictates what or how these type of constructions should be constructed as? Obviously, each town/area has its own regulations, but what should I look for when researching?