Definition — the physical difference
A central AC uses a single outdoor condenser paired to a single indoor coil sitting on top of your furnace. All cooling flows through your existing supply and return ductwork — one thermostat controls the whole house.
A ductless mini-split uses one outdoor condenser paired to one or more indoor heads (wall-mount, floor-mount, or ceiling cassette) — each with its own remote and its own thermostat. Refrigerant runs to each head through a small line-set through the wall.
A ducted mini-split is the hybrid: an inverter-driven condenser paired to a small horizontal air-handler that ties into a portion of your ductwork — often used to cool an upper storey while the existing AC handles the main floor.
When to use each — a decision guide
Choose central AC when you already have well-sized ductwork and want one thermostat to run the whole house. Best for most 1990s+ GTA new-builds with proper trunk-and-branch duct systems.
Choose a ductless mini-split when you have no ductwork (older Toronto and Scarborough century homes with radiator heat), when you have a stubbornly hot upstairs the central AC can't reach, or when you need cooling in a specific space like a finished basement or bonus room over a garage.
Choose a multi-zone (two or three indoor heads on one outdoor unit) when you want independent temperature control per bedroom — a common ask in resale-market renovations.
- No ductwork → mini-split
- One stubborn hot room → single mini-split (or ducted mini-split add-on)
- Whole-house, ductwork already good → central AC
- Whole-house, no gas → multi-zone heat-pump mini-split
Failure modes — what to watch for
Mini-splits fail most often at the flare connections between the indoor head and the outdoor unit. A properly torqued and pressure-tested install lasts decades; a rushed install leaks refrigerant slowly and fails within a couple of years.
Central AC fails most often on the condensate drain (see 'Signs your AC needs repair') and — in older systems — the outdoor fan motor bearings. The ducts themselves rarely fail; the system attached to them does.
A ductless install with the head mounted above the bed will drive the homeowner crazy every night when it kicks on. Placement is a design decision, not an afterthought — insist on walking through it before install day.
Proof — cost and efficiency
A single-head 12,000 BTU mini-split runs roughly $4,000–$6,500 installed in the GTA depending on the brand and how easy the line-set path is. A whole-home central AC replacement typically runs $5,500–$9,500 depending on the tonnage and the condition of the existing pad, electrical, and drain.
Modern inverter mini-splits reach SEER2 20+ (some models 24+) because they can modulate down to a small fraction of rated capacity — they're often more efficient than a single-speed central AC per BTU delivered.
Action — combining them
Many GTA homes end up with both: central AC on the main floor and a mini-split zone for the bonus room over the garage or the finished basement. The two systems don't fight each other as long as their thermostats are set with a reasonable setpoint spread.
Metroheat quotes both options where they apply, and we'll tell you when a duct-fix (a new return, or a properly sized branch to the master bedroom) would solve the same problem for less money than a ductless addition.