in another thread a question was askes about a 19 seer system and you replied:
In most climates, the huge premium you pay for the ultimate equipment will have NO economic payback. There could be some advantages in comfort & humidity control, but don't look for those thousands back in energy savings usually. Putting that extra towards windows, window tint, insulation, duct sealing, all could pay back so much faster.
At what rating will you realise a savings that will be cost effective? depends on the climate doesnt it?
Most of our customer buy higher SEER systems for better comfort,better warranties,more features etc..
Hard to justify STRICTLY on payback-- but when you consider humidity control,noise levels and IAQ-- high seer units are a good value for many.
Gotta figure climate/usage and juice rates. Around here with a moderate summer and very low rates, 10 SEER is about all that makes economic sense. In steamy Florida or expensive California, then high SEER is the smart move. But those 2 stage units are so pricey I question any economic payback. I suppose they have some comfort advantages but unless someone is loaded, as I mentioned probably better places to put the big bucks they command.