AC Installation in Duncan, OK
A new air conditioner in Duncan will run 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
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Five months of Duncan summers ask a lot of a new air conditioner
From May through September your air conditioner runs against afternoons that average 93°F. That is five months of the compressor cycling on, day after day, to keep the house at a set temperature while the air outside stays hot.
Stephens County has also seen 104 hail events and 67 damaging wind events over the past ten years, with hail up to 2.75 inches recorded. The outdoor unit sits exposed to that, so the condenser coil and fan are worth asking about when you install one. Any new central air conditioner installed today has to meet a federal minimum of 14.3 SEER2, so that baseline is already set before you pick a model.
- 5 months
- May through September, your air conditioner is on duty
- 93°F
- the average summer afternoon it cools against
- 104 hail events
- in ten years, and hail bends the fins on outdoor coils
- 13.4 SEER2
- the federal minimum any new unit must meet
NOAA nClimDiv, 1991–2020 normals
Going above the federal minimum saves little here, about $20 a year.
Estimates for a typical Stephens County home, from EIA household energy data, Oklahoma fuel prices and NOAA climate normals. Your home will differ.
Oklahoma requires HVAC contractors to hold a state license.
The Construction Industries Board is the state agency that tests and licenses HVAC contractors in Oklahoma. That license belongs to the contractor, not to any one job, so the same license covers this installation and the next one they do after it.
For this job, the license is what tells you the person in your house has been tested and is on record with the state. On top of that, most cities and counties in Oklahoma require a permit for an air conditioner installation, along with an inspection once the work is done. That inspection is the local building office's check that the installation was done right, separate from the state's license.
Source: Oklahoma State Legislature
- What size air conditioner does my house need?
- There is no single number that fits every house. A contractor works this out with a load calculation, not a tape measure. It accounts for your insulation, your windows, your ductwork, and how much shade your house gets. Summer afternoons here average 93°F, and an undersized unit shows that fast. It runs constantly and still can't keep the house cool. An oversized unit has its own problem. It cools the air quickly then shuts off before it pulls the humidity down, so the house feels clammy even though the thermostat says it's cool. Ask for the load calculation rather than a match to the old unit's size, especially if the house has had windows or insulation added since that unit went in.
- Should I replace the whole system or just the outdoor unit?
- In most cases, replace both together. The outdoor condenser and the indoor coil are matched to work as a pair. Put a new condenser on an old coil and the system often runs at lower efficiency than either part is rated for. It can also void the warranty on the new unit. If the outdoor unit has failed or worn out, the coil next to it has usually seen the same years of wear. A contractor can check the coil's condition and tell you honestly whether it has a few more years left in it.
- Do HVAC contractors in Duncan need a state license to work on my home?
- Yes. Oklahoma requires HVAC contractors to hold a state license, issued through the Construction Industries Board. That license covers the contractor as a business, not each individual job. Installing an air conditioner in most cities and counties also needs a permit from the local building office, with an inspection once the work is done. Ask whoever you hire whether they are pulling that permit.