The type of air ducts you have is called flexline. For short lengths, flexline can be cleaned using a point of contact cleaning method. Using a soft bristle brush at a low-speed setting, with a vacuum line behind the brush head. For long lengths, flexline is cleaned by drawing the ventilation line into negative air through a vacuum collector and agitating the debris from the walls of the air ducts towards the vacuum collector with compressed air.
That sounds like a dryer duct that goes from wall to dryer. If that's in the walls then that may be an isdue. Not sure. You'll need to ask them.
Thanks! Your answer is awaiting moderation.