I'm new here so I apologize if this is not the correct forum.
I have a contractor wanting to do work on Wed so this is urgent and your help is HIGHLY APPRECIATED!
I hired a "green" company to make my central heating/air, and home in general, more energy efficient and increase the comfort level.
After increasing attic insulation to R39 and duct sealing, I still have LARGE temperature differentials (average 4-5 degree delta from the rest of the house) in 2 of the rooms - the ones completely opposite side of the 2300sqft house from there the air intake resides.
The contractor, free of charge, wants to install a new return in the small hall way by the two rooms.
I want to ensure they are not going to make the system less efficient or cause other problems.
The central air unit is 12 year old 5 Ton (I think) Carrier split system Prod 38CKC060-311-9; Model 38CKC060-310-9 ... the AC unit was just checked out by an authorized servicer and it is in perfect condition.
The "problem" rooms are ~60-70 foot of duct work from the central unit (registers are in a Y config off the branch from that side of the attic), and the existing air-return has ~8-10 foot of duct connecting it to the unit.
... so you can see the length of the returns would have a major difference. I'm worried about this, and the sizing for the ducts themselves to ensure we are actually pulling air from the new air-return and not just wasting time or creating inefficiencies.
Please see crude drawing as reference. I show the main registers, there are several small ones (4-6") in closets, entry, etc I did not put on there.
Thank you in advance!