If your home already has good ductwork, central air is usually the cheaper and simpler way to cool the whole house. If it doesn’t have ducts, or you only need to cool a few rooms, an addition, or a hot upstairs, a ductless mini split is usually the better choice: no ductwork to install, higher efficiency, and room-by-room control.
Here’s how the two compare on cost, efficiency, comfort and maintenance.
Quick comparison
| Ductless mini split | Central air | |
|---|---|---|
| Needs ductwork | No | Yes |
| Typical installed cost | $3,500 to $7,000 per zone; $12,000 to $25,000 for 4 to 5 zones | $6,000 to $12,000 with existing ducts |
| Efficiency | Very high (often 20+ SEER2); no duct losses | 13.4 to 20+ SEER2; ducts can lose part of the cooling |
| Room-by-room control | Yes, each zone has its own setpoint | Usually one thermostat (zoning costs extra) |
| Heating | Most are heat pumps (heat and cool) | Only if it’s a heat pump; otherwise AC only |
| Appearance | Indoor head visible on each room’s wall or ceiling | Hidden; only vents are visible |
| Air filtration | Washable mesh filters in each head | Central filter (can use MERV 11 to 13) |
| Maintenance | Clean filters monthly in each head; annual service | Change one filter every 1 to 3 months; annual service |
| Typical lifespan | 12 to 20 years | 12 to 15 years |
Costs are typical U.S. ranges and vary widely by home, number of zones and region.
How a ductless mini split works
A mini split has an outdoor compressor connected by a small refrigerant line set to one or more indoor units (called heads) mounted on a wall, ceiling or floor. Each head has its own fan and its own setpoint. Installation needs only a 3-inch hole through the wall for each line set, so there’s no ductwork and little disruption to the home.
Single-zone systems pair one outdoor unit with one head. Multi-zone systems connect two to five or more heads to a single outdoor unit.
Cost: which is cheaper?
For a home with good existing ducts, central air almost always costs less to install for whole-house cooling. See central AC replacement cost.
For a home without ducts, installing new ductwork for central air often adds $5,000 to $15,000 or more and can mean opening walls and ceilings. A multi-zone mini split is usually less invasive and often similar or lower in total cost.
For one problem area, a single-zone mini split ($3,500 to $7,000) is far cheaper than any central solution. It’s a common fix for a hot bonus room, a garage conversion, an addition, or a second floor that the central system can’t keep cool. See AC running but upstairs is hot.
Efficiency and operating costs
Mini splits are among the most efficient systems available:
- No duct losses. Ducts that run through attics, garages or crawl spaces can lose a meaningful share of their cooling to leaks and heat gain. Mini splits deliver air directly into the room.
- Inverter compressors. Most mini splits use variable-speed compressors that ramp up and down to match the load instead of cycling fully on and off.
- Zoning. You only cool the rooms you’re using.
A modern variable-speed central system with well-sealed ducts inside the conditioned space can come close, but in homes with leaky attic ducts, mini splits often have a real advantage on monthly bills.
Comfort
Mini split advantages: each room can be set to a different temperature; quiet indoor operation; excellent humidity control at low speeds.
Central air advantages: even airflow through the whole house from hidden vents; one thermostat to manage; better central filtration with higher-MERV filters (see MERV 8 vs. 11 vs. 13).
A common complaint with mini splits is that a single head in an open area doesn’t reach closed-off bedrooms well. Good design, with one head per room that needs cooling, avoids this.
Heating
Most mini splits are heat pumps, so they also heat efficiently. Cold-climate models can heat effectively well below freezing. A central AC, by contrast, only cools unless it’s a central heat pump. If you’re also thinking about replacing your heating system, read our heat pump vs. furnace comparison.
Appearance
The biggest objection to mini splits is the indoor head on the wall. Options to reduce its visual impact include ceiling cassettes, floor consoles, and concealed “slim duct” units that hide in a closet or ceiling and serve one or two rooms through short ducts. These usually cost more than standard wall heads.
Maintenance
- Mini splits: rinse each head’s washable filter about once a month during heavy use, keep the outdoor unit clear, and schedule professional cleaning of the indoor coils and blower wheels every year or two. Neglected heads can develop mold and odors.
- Central air: change one filter every 1 to 3 months and schedule an annual tune-up. See our HVAC maintenance checklist.
Which should you choose?
Choose central air if:
- Your home already has ductwork in good condition.
- You want to cool the whole house evenly with hidden vents.
- You prefer one filter and one thermostat.
Choose a ductless mini split if:
- Your home has no ducts (older homes, homes heated with boilers or baseboard heat).
- You need to cool one or a few specific rooms, an addition or a converted space.
- Your central system can’t keep the upstairs comfortable.
- You want the highest efficiency and room-by-room control.
Consider both: many homes keep central air for the main floors and add a single-zone mini split for a problem room.
Frequently asked questions
Is a mini split cheaper to run than central air?
Often yes, especially compared with older central systems or ducts in hot attics, because mini splits avoid duct losses and use inverter compressors.
How many mini split heads do I need for a whole house?
Usually one head per room or open area you want to condition. A typical 3-bedroom home might need 4 to 6 heads, which is when costs climb.
Can a mini split cool a whole house?
A single head can cool an open floor plan but won’t reach closed rooms well. Whole-house mini split systems use multiple heads.
Do mini splits increase home value?
They can be a selling point in homes without ducts, especially because they provide both heating and cooling.
Disclaimer: this guide is for general information. Get a load calculation and quotes from licensed HVAC contractors before choosing a system.