Mini Split Installation in Madison, WI
A new system here will heat from October through May and cool from June through August every year. Tell us about the house, and a licensed contractor who covers Dane County will get in touch.
Tell us about the job
It takes about a minute.
Dane County asks for heat most of the year
Your mini-split will run from October through May, eight months a year, then again in June through August when afternoons average 81°F. Only a few weeks in spring and fall fall outside that.
Winter nights average 14°F here, so the unit going in needs to keep producing heat at that temperature, not just when it's mild out. Every split system, ductless included, has to meet a federal minimum of 14.3 SEER2 for cooling and 7.5 HSPF2 for heating. That's the floor everyone builds to. At 14°F, a unit built only to that floor and one sized and chosen for real cold don't perform the same.
Dane County has seen 22 winter storms and 128 damaging wind events over the past ten years, and outages follow storms like that. In 2024, 18% of Wisconsin households went at least a full day without power. A mini-split needs power to run, so that's worth asking about before you install one.
- 8 months
- October through May, your system heats
- 3 months
- June through August, it cools
- 14°F
- the average winter night it heats against
- 81°F
- the average summer afternoon it cools against
NOAA nClimDiv, 1991–2020 normals
Wisconsin requires contractors to register with the state.
Registration means the business is on file with the Department of Safety and Professional Services. Nobody tested this contractor on how to run refrigerant line or size a mini-split for a home. It's a record that a company exists and can be found, not a credential anyone earned. Dane County can't require its own HVAC license on top of that either, since Wisconsin doesn't let counties or cities set that kind of rule.
In most cities and counties, a mini-split installation needs a permit from the local building office, with an inspection once the work is done. That inspection is what this state relies on to catch a bad installation, since the registration itself does not.
Sources: Wisconsin Legislative Reference Bureau · Wisconsin Department of Safety and Professional Services
- Is a mini split worth it?
- For the right space, yes. A mini split heats and cools without ductwork, so it works well for an addition, a garage, or a home that relies on window units or space heaters. Madison winters get cold, down to 14°F on average on winter nights, so check that the unit you're looking at is rated for cold climate performance before you count on it as your only heat source in January.
- How many rooms can a mini split cover?
- A single outdoor unit can run one indoor head or several, up to eight on some multi-zone systems. Each indoor head is sized for the room it serves, so a contractor will look at the square footage and layout of each space before deciding how many zones you need. More zones give you more control room by room, but each one adds to what the outdoor unit has to run.
- Can a mini split heat a whole house?
- It can, if it's sized and placed for that. A multi-zone system with an indoor head in each main room can heat a whole house, and cold climate heat pump models are built to keep working down into single digits. Madison needs heat from October through May, so a contractor will size the system against your coldest nights, not just an average day, to make sure it keeps up all season.