I'd appreciate using you as a sounding board. I have a two storey house with full basement. It has hot water baseboard heat and I would like (need) AC.
As I see it the two options are a ductless split or a high velocity unit.
The guy spec'ing the ductless split is suggesting only two air exchangers (and compressors) one for the top floor and one for the ground floor. He is suggesting 12,000 btu Mr. Slims. The top floor is 4 bedrooms making 850 square feet. The first floor is 5 rooms making 1300 square feet. The basement is another 1300 square feet (reference only - no AC needed in the basement - although humidity control is). It is not open concept and was built in the 60's and has no upgrades with respect to insulation or windows.
My concern is that the two exchangers are not adequate and I would have far too great a temperature difference between rooms - if not some rooms completely 'unconditioned'. Of course all doors would need to be kept open.
Despite my concerns this guy is firm in that they will do the trick.
Any thoughts or pearls of wisdom are greatly appreciated. Any other options are also appreciated.