Poor flow

[jmorr]

Have the common condition of poor flow in a bedroom on 2nd flow at far end of house from furnace in basement. Adding to that the original construction had a duct was run to this room thru an exterior wall (in ohio) that then uses flex duct before going back to galv steel. Every room in the house has return air vents. Now in a kitchen remodel, going to eliminate the run in the exterior wall and was thinking of changing out from a 6" diamter duct to a 7" diameter duct from truck to floor box. All the other branches in the house are 6". Also directly adjacent to the tie in at the trunk from this room is another tie in that only runs about 3'.

Thoughts on changing from 6" to 7" diameter for this situation?

[makinmoney]

Ductwork is sized to the unit capacity and the structure.....when making changes to the structure and the Ductwork you must consider the airflow affects that will happen....normally it will be bad in the end.......

Flex duct is considered a restriction of airflow.....when you use a longer run then recommended.

Before going thru a renovation.....you should consider the little cost of having an experienced person evaluate your system to ensure that it can accomodate it....

[samtheman]

couldn't hurt to incresae the size of that run, but is the size of that duct the cause of the poor airflow? typically, a 7" duct will move about 50% more air than a 6" duct, but only if that air is available at the source. you should really have the whole duct system evaluated and see where the deficiency is. it will probably end up costing a few more dollars than just increasing the size of that duct, but there is no sense spending the money if you aren"t going to be happy with the results