So I have very unbalanced and anemic airflow at the end of the HVAC ductwork at the end of a long branch. It's all rectangular ductwork except for the very end at the register where there is a 90-degree elbow that goes from rectangular to round oval elbow back to a rectangular register face. There is more than enough volume at the source of the blower, but the pressure is such that it just ends up going out the bypass at the furnace rather than making it out to that one branch at the end - it seems like it has too much resistance at the end.
Why does that one terminating end have a round oval elbow? It splays back out to a rectangular 12x8 supply register and there is no joist that I can see. Does that adapter increase or decrease airflow. Would replacing that with a rectangular elbow decrease resistance and thus increase volume of airflow?
As an aside, would removing the automatic damper at the end also improve airflow - assuming the damper does work correctly? The damper seems unnecessary since the branch is always the one calling for air as that is the one that is always under conditioned - both heat and cold.
