Mini Split Installation in Duncan, OK
A new system here will heat from November through April and cool from May through September every year. Tell us about the house, and a licensed contractor who covers Stephens County will get in touch.
Tell us about the job
It takes about a minute.
Eleven months of work for one system
Duncan asks a mini-split to run almost the whole year. Winter nights average 31°F from December through February, and summer afternoons average 93°F from then through September. Homes here need heat from November through April and cooling from May through September, eleven months out of the year with barely a gap between them.
A unit built for that kind of duty has to meet the federal minimum for split-system heat pumps, 14.3 SEER2 for cooling and 7.5 HSPF2 for heating, if it was manufactured in 2023 or later. Stephens County has also seen six winter storms and 67 damaging wind events over the past ten years, and a quarter of Oklahoma households went at least 24 hours without power in 2024. Worth asking how a new unit comes back on once the power does.
- 6 months
- November through April, your system heats
- 5 months
- May through September, it cools
- 31°F
- the average winter night it heats against
- 93°F
- the average summer afternoon it cools against
NOAA nClimDiv, 1991–2020 normals
Oklahoma requires HVAC contractors to hold a state license.
The Construction Industries Board tests contractors before it licenses them and keeps a record of who holds one. That license belongs to the contractor, not to any single job, so nothing new gets issued for your mini-split. It covers the person doing the work, based on what they already proved to the state.
The license is what stands behind the contractor on this job, but it is not the only check. Most cities and counties in Oklahoma require a permit for a mini-split installation, and an inspection once the work is done. That permit and inspection are tied to your address, and they look at this particular installation rather than the contractor's record. The state license and the local inspection cover different things, and this job gets both.
Source: Oklahoma State Legislature
- Is a mini split worth it?
- For most homes it is, especially where a room or addition never gets the right amount of heat or cooling from the main system. A mini split runs on its own thermostat, so it can hold steady temperatures in one room without pushing the rest of the house. Duncan sees winter nights near 31°F and summer afternoons near 93°F, so a mini split has real work to do most of the year here. Whether it is worth it for your house depends on which rooms are giving you trouble and what you already have for heat and air, and a contractor can walk through that with you.
- How many rooms can a mini split cover?
- A single outdoor unit can run one indoor head or several, depending on the system. A single-zone system covers one room or open area. A multi-zone system splits the same outdoor unit across several indoor heads, each with its own thermostat, so you can heat and cool separate rooms without ductwork. How many rooms makes sense for your house comes down to the layout and where you're losing comfort now, and that's something a contractor sizes room by room.
- Can a mini split heat a whole house?
- Yes, if enough zones are installed and each one is sized for the room it serves. A mini-split heat pump pulls heat from outside air even in cold weather, so it works through Duncan's winter, when nights average 31°F from December through February. Whole-house coverage takes planning for how many indoor heads you need and where they go, since one head in a hallway won't reach a closed-off bedroom. A contractor can lay out the zones your house actually needs and size each one properly.