I am going to us blown in insulation and I was thinking about around the main air conditioner duct that runs the length of the house.

I would insulate between the studs and then lay down some plywood build a fence around the main duct of 13 inches and blow in the insulation to cover the duct. I feel that this would keep the air cold with not lost from my small two ton unit.

However, would this cause condensation thus causing mold and mildew?

David H