On Sun, 17 Jun 2007 17:00:10 -0500, RT wrote:

Where I come from, rule of thumb for average constructed homes is 1
ton/500 sq ft (8ft ceiling). Of course it's not calculated but I bet
it's close to accurate for the average home where I am.

Wow, that would make for a huge appliance, sounds oversized by quite a
bit. I have a 3 ton York AC for my 2,450 sf house, and it's pretty
good, except that the attic is noticeably warmer than the rest of the
house. Anything larger would be a waste as we don't have proper cold
air returns everywhere we should on the upper floors (built in 1930,
long before central air).