I am developing my basement and need to bring the cold air return (currently installed between the ceiling joists as are the heating ducts/vents) down to the floor level. This is an after thought following framing of partition walls and electrical. The current construction of cold air returns is using a plastic (?) thin corrugated board spanning two joists, thin silver cardboard barriers at the ends with grates installed in the plastic board. The new configuration of my basement is such that bringing the cold air returns to the floor in a straight line from the current channel is not an option.
Is it OK to 'T' off of these plastic board channels with metal ducting into one of the chnnels formed by the 2x4 studs in the aritions walls? I will need to actually turn about 180 degrees (2 x 90 degree elbows) from the original flow direction with this ducting. Does the flow direction matter or do you just need some sort of flow path for return air?
Thanks Redline. So if I have to I can use large diameter metal ducting to connect the new cold air runs from the original run? I take it by "the same" size" you are reffering to the size of the intake vent or the intake duct (or both?)?