Basic Picture, Montreal, Quebec, 3 Story House (Main Floor + Upstairs = 2500SF, basement about 1200SF) Built 1976.
I had a blower test done, ACH = 8.06 @ 50 PA (about .34 under normal conditions)
I have cold / hot spots on my third floor due to improper duct work/sizing.
Run 1 vent to the attic and new registers in the ceiling of each room: Plus balance the system. I agree with this. AND
Cancel all the existing air returns and make it 100% return in the basement.
To do this he will need to install 3 sets of transfer grills (2 walls and 1 door). BTW, we leave our bedroom doors open, so that's not a concern.
1) Does it make a difference where the returns are located?
2) Obviously he feels the current returns are insufficient, but why does he want to cancel the existing? Why not just add.
3) Sorry I can't quote verbatim: But he told me that 100% return in the basement will be more efficient in winter and summer. In summer it will draw in the already cooler basement air first, and in winter draw in the ___ air, and this is the ideal system.
4) I have read a lot in the forums about zoning.
I'm confused as to it being good or bad. Now I could easily add motorized zoning, 1 zone for my 3rd floor and 1 zone combined basement and main floor. Please answer, if installed correctly is this good or just a sales pitch. (2 stage, VS)