I'm ready to replace my 20 year old 10 Seer gas furnace/AC with a full Trane
system. I am confused by all the options (well at least I decided on the
brand), but what I'd really like to know is which units represent the best
balance between short-term cost and efficiency in the long run (especially
the AC part)? Initially I'm thinking, maybe 15 Seer? Living in warm
Southern CA my gas costs in the winter are low but in the summer the AC
electricity costs are very high. Since they don't post the price of the
systems online it is a bit tricky to know ahead of time how to balance this.