This gets presented as a technology question. It's mostly a ductwork question: what you already have, what condition it's in, and whether the space you're trying to cool was ever part of the plan.
Central air is usually the answer. The expensive infrastructure is already in the walls, one system handles the whole house on one thermostat, and replacing equipment is straightforward.
The important word is "good". Ducts that leak, are undersized, or have been extended into rooms they were never sized for will hold back any system you connect to them. That's worth measuring before you buy anything, because it changes which system makes sense.
Ductless changes the maths. A garage conversion, a casita, an addition, an older house that was never ducted — running new duct into those means opening walls and ceilings, and the construction can cost more than the equipment.
A mini split skips that entirely. A small penetration for the line set, a head on the wall, a condenser outside. It also avoids the losses ductwork causes in the first place, since there's no duct to leak.
The most common real-world version of this question isn't whole-house. It's one room that never keeps up while the rest of the house is fine.
Pushing the central system harder to satisfy that room means overcooling everywhere else and running up the bill. A single mini split on that room, on its own control, is frequently both cheaper and better — and it's a case where the smaller job is the right answer.
Existing duct condition, how many rooms need to change, whether walls would have to be opened, and whether zones need separate control. Those four answer it most of the time.
We look at all four before quoting either one. A load calculation tells us what size, and the duct inspection tells us which kind — and we'll tell you when ductless is the cheaper answer even though it's the smaller sale.
We'll inspect the ductwork and run the load calculation before quoting anything. Call or text.
