I’m in the process of making my 1950’s home more energy efficient.
I have been repairing, upgrading, and rerouting some the ductwork but have a question that I haven’t ben able to find an answer.
I have a long run of 4" duct that runs all the way to a back upstairs bedroom.
I have access to the first 15 feet in the basement and about 8 feet at the bedroom end. I do not have access to the middle section that runs up the wall between the two. I would like to boost airflow to this bedroom.
Should I:
1.) change both sections I can access to 5" and leave the 4" section in the middle?
2.) change the first section in the basement to 5"
3.) change the last section at the bedroom to 5"
4.) leave the whole run 4"
I understand there’s the Bernouille effect here, but in this case, would it boost heat/air flow to that room.