I appreciate you guys and the help offered. I want to be a well informed consumer. ..
I currently have 8 year old Goodman 10 seer 4 ton split unit. I want to swap this out with a newer system because the old one has coil leaks. This is my downstairs system. The upstairs is separate and will not be replaced.
Three of my potential 4 install companies reps have raised the issue of my intake. The current intake is 16" flex duct about 7 feet long and has a 90 degree bend. The intake of the duct is ovaled to 14"x16" and sits in the floor of a chamber under my stairs that is about 18" deep, 28" wide and about 36" tall. There is a grill with tight levours for the intake on the wall that takes a 24" by 30" filter. I use a Filtrette filter that has cardboard reinforcing so the actual surface area of the filter is less than 24x30 although it is pleated.
Contractor 1 wants to use the current system, just swap out the levour grill to one that has bigger slats.
Contractor 2 wants to increase the intake to 18" and expand the chamber under my stairs to accommodate a 30" x 30" filter.
Contractor 3 says I need more intake. He wants to add a separate second intake somewhere in another area. He states expanding the current intake to 30x30 will do the trick although it isnt to TVA specs and wont qualify for TVA financing.
Airflow though the home I dont think is an issue as there are at least 1" gaps under all doors with hardwood floors throughout. Partially open doors will slam shut sometimes when the system starts.
Thanks for your comments. . .