We are getting prices on a 16 seer & an 18 seer unit. What is the difference in running costs?

The 18 will cost you up front but you will get it back in the long run. However, do you have plenty of insulation? Double pane windows?

We went with the 4 ton 18seer Trane. The difference is, the 18 seer also has a 2 ton unit that switches on to keep the humidity low while the 4 ton switches off. The 16 seer is just one 4 ton unit. Should save $$$.

The 18 will cost you up front but you will get it back in the long run. However, do you have plenty of insulation? Double pane windows? yes, we have very good insulation and double pane windows, plus a large screened in porch on the back of the house (east) and the front (facing west) we have solar screens.