Poor airflow from too many bends?
I have one register in my upstairs that has absolutely anemic airflow. It’s one of the farthest from the air handler, enters the upstairs via an unconditioned knee wall attic, and has what seems like a ludicrous path for the air to take before getting to the wall stack duct that takes it up to the 2nd floor. Photo attached.
The rectangular supply branches off into a round duct that goes 90° up and over the return duct, goes straight for a few feet then bends down 90° and turns 90° to the left, before a short straight run, finally turning 90° upward into the wall stack.
The portion in the attic is a straight run of flex duct to the wall register, which I haven’t looked at in a while.
How significant of an effect could this odd duct-routing have on the low level of airflow at that register? I know more bends generally mean worse airflow, but does the way it doubles back have some negative effects independent of the bends? Could a more direct duct route improve upstairs comfort before tackling other factors with the ductwork?
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