Where a mini split makes sense
ENERGY STAR names the usual places: additions, garages, sheds, barns and other spots where extending ductwork is hard. That list takes in log homes too. One of the mini splits on our Google profile sits right against the logs of a log house, where running ducts would mean cutting through solid timber.
A mini split also fixes the one room that’s always wrong — the bonus room over the garage, the sunroom, the back bedroom at the end of a long duct run — without touching the central system.
Single-zone or multi-zone
A single-zone system is one outdoor unit and one indoor head. A multi-zone system runs several heads from one outdoor unit, each with its own setting. The Mitsubishi Electric multi-zone heat pump on our profile, on a pad against white-painted brick, is that kind: one condenser outside, several rooms inside.
What the install involves
- The outdoor unit, set level on a pad or a wall bracket
- A small hole through the wall for each indoor head
- The insulated copper line set and the condensate line, run neatly up the outside wall — one of our photos shows one climbing vinyl siding
- The indoor head, mounted high on the wall, and its remote or thermostat
- Pressure-testing and charging, then a run in both heating and cooling
Living with one
Expect it to run more steadily than a central unit, at a lower speed and a lot more quietly. The heat-pump models heat through the winter as well, so a garage shop or an addition gets both seasons from one install. Keep the filters in the indoor heads clean, and book a check-up once a year like any heat pump.
If you have ducts that simply aren’t doing their job, it may be cheaper to fix the ducts or replace the central system than to add heads room by room. We’ll say which.