Originally Posted by BayouBiker
You can make a cheap flow tester with some paper and scotch tape. a paper cylinder to fit snugly around the black plastic duct register cover the end with a half moon paper and the other half use tape as a hinge and another oversized half moon as a flap. then check each register to see if the flap opens about the same amount.
Brian, good one nice and simple.
Each model, different routing and flow. A good visual insp and look for maybe something that fell from storage onto hose or restrictions to return air flow. My furnace is under the sink and pulling the shelf allows for a good peak at the hoses. Then follow to distribution registers.
In one of Darren's videos the bench test one IIRC he said do not put any type of filter in the return air flow.
Sitting here waiting for the rains to hit from Sally a bit latter.