Ductless minisplit to cool antique 3 level house?
We have an antique house, circa 1900, with basically original envelope: single glazed double hung windows (with basic storm windows added), probably little insulation in the walls (where insulation is visible in the attic it is a wool-based material).
Total square footage is 4000 sq ft in 3 levels above the basement. We’re in southern New England near the coast.
HVAC contractors we’ve seen so far are in favor of whole house high velocity AC, in the range of 6 tons to 7.5 tons and a cost of 50K (not including electrical and finishing). They tell me minisplits would be even more expensive up front.
I’d like to explore minisplits for:
(1) ability to use only where needed;
(2) lower labor cost;
(3) ability to install only where needed;
(4) ability to expand over time.
As a bonus, it might be nice to use it to heat 1 or 2 bedrooms while letting the downstairs drop to low 60s at night. (hot water heat).
Am I totally off here in wanting to explore minisplit cooling? I just did a bit of research and saw one 3.25 ton unit with 5 heads for under 4K. I might be picky about the heads (will want cassettes in some locations) but hard to see this ballooning into a 50K project.
Any advice most appreciated!