o.k. will TRY and condense this! I took over a 1/2 done home. walls etc already up. I have a bsmt, getting ready to do HVAC. still exposed joists ( ceiling in bsmt) can pan etc.. BUT.. I am thinking of running (3) total returns. (1) will be in the hall, and at the floor, the other (2) will go through the closets ( in a metal duct), then flex in the attic to a high wall grill at my cathedrals.. (1) on each side, as I have a long home, with a greatroom in front, (cathedral), then the hall, other rooms, ( with the attic), and then a master suite ( cathedrals)
1)...what size wall stack/ returns in the closets.
2)...do they make a collar then to transition from that to insulated flex in my attic?
I am putting in a ntrl gas, 90k furnace with a 3 ton a coil, not sure of CFM's at this point... ( i.e. like a 4 ton blower etc..)
I appreciate any feedback!