Is ductless or central air cheaper to install?
Central air is usually cheaper to install in a house that already has ducts ($5,200–$9,800 with us), while a ductless mini-split ($4,200–$12,500 with us) is usually cheaper in a house without them, especially for one to three rooms. Whole-house cooling in a radiator home is the close call.
Key points
- The ducts decide it: with a ducted furnace, central AC is usually cheaper for the whole house.
- Our installed ranges: central AC replacement $5,200–$9,800; ductless mini-split $4,200–$12,500.
- For one to three rooms without ducts, ductless is almost always the cheaper route.
- Whole-house cooling in a radiator home comes down to multi-zone ductless, a high-velocity system or new ductwork, each priced on the house.
- A ductless system is a heat pump, so it also heats in spring and fall; a central AC only cools.
Central air is usually cheaper to install when the house already has a forced-air furnace with supply and return ducts, because it uses what's there. A ductless mini-split is usually cheaper when the house has no ducts, or when only one to three rooms need cooling, because it skips the most expensive part of the job: building a way to move air. With us, central AC replacement runs $5,200–$9,800 installed and a ductless mini-split $4,200–$12,500. The close call is cooling every room of a house that has radiators and no ducts.
Start with what's in the basement
Most houses we see in the Twin Cities suburbs and the towns around them have a gas or propane furnace with ducts. Adding or replacing central AC in those homes means an outdoor condenser, an indoor coil on top of the furnace, a refrigerant line set and a circuit. The ducts, blower and returns already exist.
Older city homes are different. A lot of 1900s–1920s houses in Saint Paul and Minneapolis heat with a boiler and radiators and have no ducts at all. Some ducted homes also have rooms the ducts never reached well: a finished attic, a three-season porch, an addition, a bonus room over the garage.
Which is cheaper for your house
| Your house | Usually cheaper | Why |
|---|---|---|
| Forced-air furnace, ducts reach every floor | Central AC | Uses the existing ducts, blower and returns |
| Ducted house with one hot room | Single-zone ductless | Cheaper than extending ducts into finished space |
| Radiator house, one to three rooms | Ductless | No ducts to build |
| Radiator house, every room cooled | Price multi-zone ductless and high-velocity side by side | Head count against tubing runs |
| Story-and-a-half with a hot upstairs | A ductless head upstairs, even with central AC below | Ducts rarely reach those rooms well |
| Furnace also near the end | Price central AC with the furnace, and a heat pump | Matched equipment, one install |
How much do central AC and ductless cost installed?
Our installed ranges, from our own price list:
| System (installed with us) | Range |
|---|---|
| Central AC replacement | $5,200–$9,800 |
| Ductless mini-split | $4,200–$12,500 |
For outside context, HomeGuide's 2026 national cost guides give these typical ranges. They're national averages, not our prices:
| System (national typical range, HomeGuide) | Range |
|---|---|
| Ductless, single zone | $2,500–$6,000 |
| Ductless, 2 zones | $4,500–$8,000 |
| Ductless, 3 zones | $6,500–$11,000 |
| Ductless, about 5 zones (whole home) | $10,000–$15,000 |
| High-velocity small-duct system | $3,500–$15,000+ |
We don't have a sourced figure for building new ductwork into a house that has none, and we won't guess at one. It depends too much on the floor plan, the attic and how much plaster has to be opened. Our guide to AC replacement cost in Minnesota goes deeper on the central AC side.
When each one wins
Central AC
- The house has a working forced-air furnace and reasonably sized ducts.
- You want the whole house cooled from one thermostat.
- The furnace is newer, or due for replacement at the same time, so the indoor coil and blower can be matched.
- You'd rather not see indoor units on the walls.
In that house, a central AC install replaces or adds the outdoor unit and coil and leaves the ductwork alone. Our AC installation page walks through what's on that quote. The main cost swings are system size, efficiency tier, whether the line set can be reused, and whether the old coil matches the new condenser.
Ductless
- There are no ducts, and you want to cool one to three rooms.
- One area of a ducted house runs hot and extending the ducts isn't practical.
- The space is an addition, porch, garage, attic room or lower level with its own schedule.
A single-zone ductless mini-split is one outdoor unit, one indoor head, a small line set through the wall and a circuit. No walls get opened for ducts. That's why it's so often the cheapest fix for a single hot room. Brands like Mitsubishi Electric sell cold-climate versions that also heat well into winter.
What drives the price in a central AC or ductless quote?
Two quotes can look far apart until you line up what's in them. Items that move the price:
Central AC
- A new line set when the old one is the wrong size, damaged, or doesn't exist because the house never had AC.
- An indoor coil that fits the furnace cabinet. A coil that doesn't match the new outdoor unit costs efficiency and can cause problems.
- A condensate drain for the coil, and a pump if there's no floor drain nearby.
- A dedicated circuit and an outdoor disconnect, sometimes with panel work.
- Airflow. If the returns are undersized, the blower can't move enough air over the coil, and the upstairs stays warm no matter what the condenser costs.
Ductless
- Line-set length and route, especially when the outdoor unit can't sit right behind the indoor head.
- Condensate. Heads on interior walls may need a small pump.
- Head type. Wall heads are the least expensive; ceiling cassettes and ducted units cost more to install.
- Mounting. Outdoor units here go on a stand or bracket above the snow line.
Ask for these as separate lines. It makes quotes comparable and shows you where the money goes.
How do you cool a whole house that has no ducts?
This is where the answer depends on the house. There are three routes:
- Multi-zone ductless. One or more outdoor units feeding a head in each main room. Price climbs with every head, and the heads are visible. Our guide to multi-zone layouts covers where the heads go.
- High-velocity small-duct. An air handler in the attic or basement pushes air through small flexible tubes to round outlets in ceilings or floors. It fits old plaster homes with less demolition. See high-velocity HVAC for older homes.
- New conventional ducts. Sometimes possible through closets and chases, often the most disruptive.
In a story-and-a-half bungalow where the upstairs roasts, a two- or three-head ductless system is often the practical answer. In a big foursquare where you want every bedroom cooled, it's worth pricing ductless and high-velocity side by side. Our page on ductless mini-splits in Minneapolis covers how that plays out in the city's bungalows and boiler houses.
Can a ductless mini-split heat as well as cool?
A central air conditioner only cools. A ductless mini-split is a heat pump, so it can also heat on mild days. In a radiator house, that means cooling in July and taking the chill off in October without firing the boiler. Cold-climate ductless models keep making heat well below zero, but output drops as it gets colder, so the boiler or furnace stays for January. Our heat pump page covers that trade.
On running costs, ductless systems modulate their compressors and only condition the rooms you're in. Central systems in Minnesota have an advantage of their own: the ducts usually run through the basement, inside the heated part of the house, so less of the conditioned air is lost on the way.
What Minnesota rebates apply to central AC and ductless?
- Xcel Energy lists rebates for central AC with a quality installation and for mini-split and cold-climate mini-split heat pumps. Its heat pump rebates go through Xcel's Trade Partner Network, except that mini-splits can be self-installed for the rebate, and some measures need an Xcel-registered contractor. Xcel says heat pump installs must be complete by December 31, 2026.
- Electric co-ops such as Dakota Electric and Connexus run their own ductless and heat pump rebates.
- The federal 25C tax credit ended for equipment placed in service after December 31, 2025, and Minnesota's HEAR and HOMES rebates had not launched as of mid-2026.
Programs change every year, so check the current terms before you sign. Our Xcel and CenterPoint rebate guide links the program pages, and we help with the paperwork where the program allows it.
What to do next
Know which rooms you actually need cooled before you get quotes. Then call 612-429-3465, any day from 7am to 9pm, and we'll look at the ducts, the walls and the electrical panel and write up the options that fit the house, each at a flat rate. Installs carry our 2-year labor warranty on top of the manufacturer's parts warranty.
Questions
Can I add central air to a house with a boiler and radiators?
Yes, but it needs its own air distribution because the boiler has none. The options are a multi-zone ductless system, a high-velocity small-duct system with an air handler in the attic or basement, or conventional ductwork fitted into closets and chases. Which is cheapest depends on the floor plan, attic access and how many rooms you want cooled.
Is a ductless mini-split cheaper to run than central air?
Often, for the rooms it serves. Mini-splits use inverter compressors that slow down instead of cycling off, and you only cool the rooms you're using. In most Minnesota houses the ducts run through the basement, inside the heated space, so duct losses are smaller than in homes with attic ducts. Running cost depends more on how you use the system than on the type.
How many ductless heads does a whole house need?
Roughly one per room or open area you want controlled, since each head only reaches the space it can blow into. Closed bedrooms usually need their own heads, and an open main floor may need one or two. That head count is the biggest driver of a multi-zone price, which is why we plan the layout before quoting.
Will a ductless system replace my furnace?
It can carry a lot of the heating in spring and fall, and cold-climate models keep working well below zero, but capacity drops as it gets colder. In most Minnesota homes we keep the existing furnace or boiler as the backup for the coldest weeks rather than removing it.
Sources
- HomeGuide cost guides (2026 editions) homeguide.com