I'm in northern NJ, here are some basics on the home:
Original forced air furnace with no AC.
"energy efficient" windows installed ~5 years ago.
2100 sq/ft home
After being miserable in the heat wave we just had, I figured I would look into adding AC. This isn't as easy as it seems!
My first quote was very vague. He would swap the furnace, add a coil on top and install a 4 ton condenser outside. He seemed to like using Goodman products; GMH8100, ZAPF4860C, and GSX1348 respectively.
The second totally took me by surprise. He wanted nothing to do with adding a coil above the furnace and was adamant about installing everything in the attic and running duct to the upstairs rooms. The two bedrooms downstairs would need a duct run down an upstairs wall (which are brand new from the kitchen remodel I'm wrapping up) but could at least be done at a later date. No word on price or specific products, he was going to work up a list. We were also talking about a furnace swap and variable speed units and so on, just that I would need a 3.5 ton unit.
I do have the usual drastic temp difference that comes with this style home. I think that the second option might be the way to go, but I'm not sure. I bet it will be way more expensive, but I would like a comfortable home.
Would the attic install be the correct way to cool my home? I have talked to no one who has even hinted about doing a heat loss calc or anything similar to that. I am aware of the program you can buy, but I think the 2 month lifespan is a little silly.