Equipment·7 min read
Ducted or ductless: which one for your house?
A decision tree based on what your house already has, not on what's newest.
A decision tree based on what your house already has, not on what's newest.
The equipment marketing treats ductless mini-splits as the modern choice and ducted systems as the legacy one. In practice, the right answer depends almost entirely on what your house already has, not on which is newer.
If your house has an existing forced-air furnace and a functional duct system, ducted air-source is usually the straightforward choice. It replaces the furnace and central AC with a single outdoor unit and an indoor air handler, using ductwork that's already in place. The main condition worth checking is duct condition: leaky, undersized, or poorly insulated ducts should be addressed as part of the swap, since a heat pump is less forgiving of duct losses than a furnace was.
If your house has no ductwork at all, common in older homes with radiators, baseboard heat, or window units, ductless mini-splits avoid the cost and disruption of installing ducts from scratch. Each room or zone gets its own wall- or ceiling-mounted head, with its own thermostat, which also means uneven use of the house, closing off a guest room, for instance, doesn't waste conditioning on it.
A hybrid case that comes up often: a house with ducts serving part of the home (say, the main floor) but none serving an addition, finished basement, or converted attic. Here a ducted system for the original footprint plus a ductless head or two for the unducted space is frequently cheaper and simpler than extending ductwork into spaces that were never designed for it.
Cost tends to favor ducted for whole-house coverage when ducts already exist (roughly $12k-$20k installed), and favors ductless for partial coverage or duct-free homes, though ductless can add up quickly per zone ($4k-$6k each) if you need to cover many separate rooms.
Comfort differs too. Ducted systems distribute air through a house more uniformly from central returns. Ductless systems let each zone run independently, which is better for rooms with very different needs (a sunny west-facing bedroom vs. a shaded north-facing office) but can create noticeable temperature differences between rooms if zones aren't used deliberately.
