Missouri HVAC Match
An outdoor air conditioning condenser unit mounted on a concrete pad next to a blue-sided residential house at sunset.

AC Installation in Farmington, MO

A new air conditioner in Farmington will run from June through September every year. Tell us about the house, and a licensed contractor who covers St. Francois County will get in touch.

Tell us about the job

It takes about a minute.

Step 1 of 3: Equipment
An outdoor central air conditioning unit mounted on a concrete pad beside a blue-sided house at sunset.

Four months of real heat is what your new AC has to handle

Summers here run June through September, and afternoons average 86°F through that stretch. That is the load a new system sits under, season after season.

Any central air conditioner installed new has to meet 13.4 SEER2, the federal efficiency minimum since 2023. Beyond that baseline, this area also sees hail and wind. Ten years of records show 19 hail events and 54 damaging wind events, with hail up to 3 inches. An outdoor unit sits outside through all of that, so how it's installed and protected matters as much as the equipment itself.

4 months
June through September, your air conditioner is on duty
86°F
the average summer afternoon it cools against
19 hail events
in ten years, and hail bends the fins on outdoor coils
13.4 SEER2
the federal minimum any new unit must meet
Isometric line illustration of a cutaway house showing interior rooms, a furnace or air handler with ductwork, and an outdoor condenser unit beside the building.
Your air conditioner works hardest from June through August.

NOAA nClimDiv, 1991–2020 normals

An outdoor air conditioning condenser unit positioned beside a blue-sided house at sunset.

A higher-efficiency unit would save about $30 a year to run in St. Francois County compared with a new unit at the federal minimum.

  • A higher-efficiency unit$210 a year
  • A new unit at the federal minimum, 13.4 SEER2$240 a year

Estimates for a typical St. Francois County home, from EIA household energy data, Missouri fuel prices and NOAA climate normals. Your home will differ.

What size air conditioner does my house need?
The right size comes from a load calculation, not the square footage of your house. A contractor looks at your insulation, your windows, how many rooms you have, and which way your house faces before landing on a number. An oversized unit cools the air fast but shuts off before it pulls the humidity out, so the house feels clammy even at the right temperature. Undersized, and it runs nonstop on those 86 degree afternoons and still can't keep up. Ask whoever quotes the job to walk you through the calculation, not just hand you a tonnage.
Should I replace the whole system or just the outdoor unit?
If your indoor coil and furnace are old, replacing just the outdoor unit is usually a mistake. The outdoor and indoor parts are matched to work together, and pairing a new condenser with an old coil can mean it never reaches the efficiency it's rated for, sometimes voiding the warranty too. If the indoor unit is only a few years old and in good shape, matching a new outdoor unit to it can work. A contractor can check the age and condition of both and tell you which situation you're in.
Do HVAC contractors in Farmington need a state license to work on my home?
Yes. Anyone installing or servicing central air conditioning in your home should hold a state HVAC license. Ask to see the license number before work starts, and check that it's current. A licensed contractor also carries the insurance that protects you if something goes wrong during the install.
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