Originally Posted by beenthere
Your basement returns are pulling more air, then your supplies are delivering to those rooms.
Your first floor is probably a bit short on return also.
Post pics of the return set up at the plenum, and at that wall.
I have yet to get pics of this, been very busy lately....
I just noticed the other day that the return vents in the 2nd floor are barely sucking anything not even enough to hold a tissue on the wall vent... but the basement vents are sucking as much as a vacume cleaner seems to.... is there any way to balance the return vents? they put no dampers or anything on the returns.. just have the fast and cheap way of doing it with the wall grill... using a joist cavity as a duct and attaching it to a return plenum basically.... even the second floor ones just go through the floor through the 1st floor walls as joist cavity ducts except for one which has a riser duct...