I have a 2,100sq ft colonial in Massachusetts built in 1985. It has a full basement that is partially finished, open floor plan on 1st floor, 4br & 2bth on 2nd, and spacious attic with fiberglass insulation on the attic floor. I have baseboard heat and no duct work.
I am looking to have central AC installed and have gotten contractors telling me different things on how the job should get done:
Option 1) 5 ton (possibly 2 stage) attic unit with ceiling registers in each 2nd floor bedroom, return in 2nd floor hallway, then 2-3 runs down through closets to ceiling registers on the first floor. 1st and 2nd floors as separate zones.
Option 2) 2.5 ton attic unit with ceiling registers in each 2nd floor bedroom, return in 2nd floor hallway; And 2.5 ton basement unit with runs to floor registers in each first floor room. Not sure where the return would be - I guess another floor register
What makes more sense from a comfort and air flow perspective?
I thought that having ceiling registers for AC would be preferable to floor registers as cool air falls. I'm not too fond of floor registers as you can drop things in them, they limit where you can put furniture and shouldn't be walked on. I suspect having 2 units would be more expensive, but might provide less cycling than one larger unit and therefor more comfort and efficiency? I would rather have the right air flow, temperature, and humidity, and cost and wall/floor repair are secondary.
All feedback appreciated.