I am getting bids for a split system for a new house. I spoke to an American Standard contractor (highly regarded) today and asked them for recommendation. I don't have the bid yet but we discussed issues like sizing and SEER and AFUE ratings. House if 3139 sq ft and architect plans provides for a spilt system (4 ton and 2.5 ton). I am located in central California (hot, relatively dry summers and mild winters).
His preliminary recommendation was to go with a 12 or 14 SEER AC (14 SEER with a 2 speed fan) and use an oversized coil to increase efficiency. I asked if this would create a problem with warranty and he assured me it would not and that using an over sized coil was a common method to increase efficiency. He said this would give me reasonable efficiency without the extra cost of an 18 SEER unit.
He recommended using an 80 AFUE system with a variable speed fan (or two stage valve? Sorry, can't remember). He said for your area the cost of a 90+ AFUE system would not be cost effective.
Contractor said he would do a calculation but said 6.5 tons for our area for the house size sounded about right.
Any comments from the professional members? Any other questions I should ask.
Thanks very much.