Our super insulated, super tight home in central Indiana is finally ready for the installation of air conditioning and fresh air. I've done my homework (I think) and so I feel I can talk intelligently with the contractors who have come to look at what we've got. Yesterday, the fourth guy out (and by the way actually was familiar with our building materials) talked quite a bit about the importance of getting enough air circulation in a tight, well insulated home even to the point of superceding whatever the Manual J load calculations show. I told him that our home (1750 sf of ranch with full basement) had a calculated load of 12K BTUH cooling (and that came from two different guys who have been out before this one). He immediately said that he would probably need to put in a 3 ton air handler to get sufficient air circulation. Is that ok? My impression has been that the air handler needed to be matched to the condenser pretty closely. In fact, the other 3 guys all came up with a 1.5 ton compressor with a 2 ton AH. His argument is that I don't want to end up with "dead air" spots in the house, but I should have at least 9 ACH through the air handler. I'm stuck! I have no idea if this guy is right or not. Any thoughts? Like I said, he actually was somewhat familiar with our construction method and has put in Apriaire's HRVs in other homes. Help!