poor install of duct work three quarter of the air space is blocked due to flec not being installed proper should have a max of 3 feet of solid duct off a unit and not sealed either not to mention install requires hard pipe to be used when passing through a structure as in a wall or floor or ceiling area and sheet metal screws

for one thing they should be fired from hvac or showed how to do it right . they used a piece of flex to make a 90 elbow. quick fix haha