By Hood Service Company · Corsicana, TX · Updated
The short version
- Ductless systems skip the ductwork, so they suit additions, converted garages and older homes without ducts.
- Central air is usually the simpler fit when a home already has sound, well-sized ductwork.
- Most mini-splits are heat pumps, so one system can both cool and heat the rooms it serves.
- A load calculation, not a rule of thumb, should decide the size of either system.
What is the difference between ductless and central air?
Central air uses one indoor air handler or furnace and a network of ducts to serve the whole house. A ductless mini-split pairs an outdoor unit with one or more indoor heads, each conditioning a single room or zone.
Both are split systems: an outdoor unit holds the compressor and outdoor coil, and refrigerant lines carry heat between it and the indoor side. The difference is how the cooled air reaches you. With central air, a blower pushes air through supply ducts and pulls it back through return grilles. With ductless, each indoor head has its own fan and coil and blows air directly into the room where it's mounted.
When does a ductless mini-split make the most sense?
Ductless shines where ducts are missing, impractical or undersized: room additions, converted garages, workshops, sunrooms, older homes without ductwork, and single rooms that never stay comfortable on the central system.
- Additions and conversions. Extending ductwork to a new space can be awkward or impractical; a ductless head needs only a small wall opening for its refrigerant lines, drain line and wiring.
- Hot or cold rooms. A bonus room over the garage or a west-facing bedroom that fights the afternoon sun can get its own dedicated head.
- Homes without ducts. Houses that rely on window units or space heaters can move to ductless without opening walls and ceilings for new ductwork.
- Room-by-room control. Each head has its own setpoint, so you can condition the rooms you're using instead of the whole house.
When is central air the better choice?
If your home already has ductwork in good shape and sized for the house, central air usually delivers whole-home comfort with one thermostat, one filter location and the indoor equipment kept out of sight.
Central systems also make it straightforward to add whole-home accessories such as upgraded filtration or a whole-home dehumidifier, because all of the air passes through one point. If the ducts are leaky, crushed or poorly designed, though, those problems carry over into any new central system, so have them evaluated first. Our guide to weak airflow and ductwork problems covers what to look for.
Some homes end up with both: central air for the main living space and a ductless head for one addition or problem room.
What are the trade-offs in efficiency, comfort and upkeep?
Ductless avoids the energy lost through leaky ducts, and many mini-splits use variable-speed compressors. Central air hides its equipment and serves every room at once. Both need regular cleaning and service to perform as rated.
- Efficiency. Many mini-splits use an inverter-driven compressor that ramps up and down to match the load. Compare any system by its SEER2 rating, and use our SEER calculator to see how different ratings compare.
- Appearance. Ductless heads are visible on the wall or ceiling; central air shows only supply and return grilles.
- Upkeep. Each ductless head has a washable filter and an indoor coil that needs periodic professional cleaning; a central system has one filter to change.
- Humidity. Both remove moisture while cooling. Correct sizing matters for either, because an oversized system shuts off before it can dry the air well.
How do you decide which system fits your home?
Start with the house, not the equipment: the condition of any existing ducts, which rooms are uncomfortable, and a room-by-room load calculation. Cost depends on the home, so a free estimate on a new system is the clearest next step.
A proper load calculation accounts for insulation, windows, sun exposure and layout, and it applies to both kinds of system. An oversized mini-split head short-cycles just like an oversized central unit. Read more in HVAC sizing and load calculations.
When you're ready, explore ductless mini-split options or request a free estimate. Hood pulls the required HVAC permits and registers new equipment with the manufacturer for you. Financing is available through Wells Fargo, Synchrony and Snap Finance, subject to credit approval and lender terms.
When should you call a technician?
- A ductless head drips water into the room or its drain line backs up.
- Ice forms on the refrigerant lines, or a head blows warm air in cooling mode.
- The system shows an error code or blinking indicator lights that don't clear after a restart.
- One room still won't stay comfortable after you've cleaned the filter and checked the settings.
- You're planning an addition or a replacement and need a load calculation.
Frequently asked questions
Can a mini-split heat my home in winter?
Most ductless mini-splits are heat pumps, so they heat as well as cool. Heating capacity drops as outdoor temperatures fall, and models differ in how well they handle a cold snap. Ask about the model's cold-weather performance and whether a backup heat source makes sense for your home.
How many rooms can one outdoor unit serve?
Some outdoor units serve a single indoor head, while multi-zone units connect several heads to one outdoor unit. The right setup depends on each room's load and the distance between the heads and the outdoor unit, which a technician can assess on site.
Will a ductless system replace my central air?
It can, but it doesn't have to. Many homes use ductless to supplement central air in a problem room or an addition. A whole-home ductless setup makes the most sense when there's no usable ductwork to begin with.
Do ductless systems need maintenance?
Yes. Rinse or vacuum the washable filters in each indoor head regularly, and have a technician service the indoor coils, blower wheels, drain lines and outdoor unit. Learn more about ductless maintenance and tune-ups.