What a New HVAC System Costs in Great Falls, MT (2027)
Adjust your home size & electric cost in Great Falls, MT
Our cost model puts a 14 SEER central air system in Great Falls, MT at $7,620 to $9,180 with equipment and labor. It is sized at 3.5 tons (about 42,000 BTU) for a 2,200 sq. ft. house. Great Falls, with about 60,000 residents, prices in line with the Montana statewide model; no city adjustment applies.
The price assumes your ducts can stay. When an installer finds crushed runs, too few returns or a dated disconnect, those repairs show up as added lines.
Installed AC Prices in Great Falls, 14 to 20 SEER
Great Falls prices by rating: $7,620 to $9,180 gets 14 SEER, $9,610 to $11,580 gets 16 SEER, $15,540 to $18,730 gets 18 SEER and $20,930 to $25,220 gets 20 SEER.
3.5-Ton Central AC: Great Falls Price vs Montana Average
| System (3.5 ton) | Great Falls | Montana average | Materials |
|---|---|---|---|
| 14 SEER | $7,620 - $9,180 | $7,580 - $9,140 | $4,780 |
| 16 SEER | $9,610 - $11,580 | $9,560 - $11,530 | $5,970 |
| 18 SEER | $15,540 - $18,730 | $15,460 - $18,640 | $9,500 |
| 20 SEER | $20,930 - $25,220 | $20,820 - $25,100 | $12,710 |
The condenser, coil and parts come to about $4,780 on a 14 SEER job and $5,970 on a 16 SEER job; everything else in the Great Falls price is installation.
The Great Falls Price Adjustment, Explained
Two identical systems can draw different quotes in two Montana cities, because labor and overhead are set locally. A 16 SEER system here costs $9,610 to $11,580, the same as the Montana average.
Whether you live near the center or the city line, the estimate holds for the 5 Great Falls ZIP codes in Cascade County. The cheapest bid is often the one that leaves out the permit, a new line set or duct sealing. Compare complete scopes, not headline prices.
The Running-Cost Side of the Great Falls Decision
We price Great Falls running costs at the Montana average of $0.177/kWh (about 19% below the national average of $0.217); if your bill shows a different rate, enter it in the form above. Montana electricity has climbed about 2.18% a year over the past decade, and the ten-year figures below assume that trend continues.
Hover or tap any year to see what each rating costs to run that season. Rates rise 2.18% a year, the MT ten-year trend.
The first point applies MT's current rate to this season; every point after it adds another year of the 2.18% average increase. Dollar figures are rounded up to the next $10.
At that rate, a 16 SEER system in Great Falls uses about 2,802 kWh a season, roughly $500 a year; a worn 9 SEER unit would cost about $880.
Upgrade Payback Finder: Your Old AC vs a New One
Pick the unit you have and the one you are considering. Figures are for a 3.5-ton system at Montana electric rates ($0.177/kWh, rising 2.18% a year).
| Installed price of the new system | $8,280 |
| Electricity saved, first year | $320 |
| Saved over 10 summers (rates rising) | $3,510 |
| Payback | 20.9 years |
| Net after 10 summers | -$4,770 |
Savings alone fall short: 9 to 14 SEER is still $4,770 behind after 10 summers in MT.
These figures treat the whole install as the price of switching from a unit that still runs. For a dead unit, only the step up from a basic 14 SEER bid has to pay back.
Old 9 SEER vs New: Great Falls Numbers
| 9 SEER | 14 SEER | 16 SEER | 18 SEER | 20 SEER | |
|---|---|---|---|---|---|
| Installation Cost | - | $8,280 | $10,440 | $16,890 | $22,750 |
| Electric Usage / Yr | 4,959 kWh | 3,161 kWh | 2,802 kWh | 2,522 kWh | 2,299 kWh |
| Electric Cost / Yr | $880 | $560 | $500 | $450 | $410 |
| Energy Savings / Yr | - | $320 | $390 | $440 | $470 |
| Payback (Rates Rising) | - | 20.9 years | 21.7 years | 28.7 years | 33.4 years |
| 10-Year Net (Rates Rising) | - | -$4,770 | -$6,240 | -$12,140 | -$17,560 |
In Great Falls, 14 SEER gives the best mix of price and savings: about 20.9 years to recover its cost against an old 9 SEER unit.
Price Plus Running Cost: Great Falls Totals
Buy Price vs 10-Year Running Cost: Total Cost of Ownership in MT
Three bars per rating: what it costs to install, what it costs to cool the house for 10 summers at Montana rates with the rate climbing 2.18% a year, and the sum. The rating with the shortest third bar costs the least to own. Tap or hover any bar to see the addition.
Lowest 10-year total in Montana: 14 SEER, $14,440 ($8,280 up front, $6,170 in electricity).
Includes energy inflation: electricity = this season's cost at today's MT rate, then each of the next nine seasons raised by the historic 2.18%/yr rate increase. Install = the typical installed price on this page. Each figure is rounded up to the next $10 on its own, so the two parts can add up to $10 more than the total.
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Matching the System to Great Falls Weather
In Montana, which our map files under climate region 1, summer days average roughly 83°F and winter days roughly 31°F. Those statewide figures feed the Great Falls numbers. Cooling hours in Great Falls are few next to heating hours, so the furnace or heat pump deserves as much attention as the AC rating.
Climate zones run from 1 (cool) to 5 (hot); Montana is in Zone 1.
Dry air in Great Falls means nearly all of the AC's capacity goes into lowering the temperature.
About 180 miles northwest of Billings, Great Falls has its own housing mix and its own prices.
Replacing the AC and the furnace together in Great Falls matches the indoor coil to the blower, which is how the cooling side reaches its rated efficiency. If a Great Falls bid calls for more than the 3.5-ton estimate, ask to see the calculation behind the bigger number.
What Great Falls Housing Means for the Job
A house on wall-furnace or baseboard heat faces a bigger project for ducted air; ductless heat pumps are often simpler. Jobs in Great Falls are mostly single-family houses that crews can reach easily, so labor stays modest.
For one finished attic or an addition, a single-zone mini-split usually costs less than extending the ducts.
Booking the Job in Great Falls
Replace an old system in spring or fall. Great Falls crews have open calendars then, and the house can go a day without heat or AC. A licensed Montana contractor who pulls the permit gives you a record to point to if a problem shows up later.
Compare Another Montana City
Same 16 SEER system, other Montana cities:
- Billings, MT (southeast, 180 mi): $9,700 to $11,690
- Missoula, MT (west, 130 mi): $9,640 to $11,620
- Bozeman, MT (south, 130 mi): $9,600 to $11,570
If you live just outside Great Falls, in Black Eagle, Sand Coulee, Ulm, Floweree and Vaughn for example, expect bids close to these.
The Montana HVAC cost guide covers statewide prices, SEER comparisons and the cost model behind these numbers. The AC size calculator gives a closer size estimate, and the heat pump calculator compares operating costs if you are weighing a heat pump.
Modeled estimates, not quotes: equipment, duct condition, access and permit fees will move the final price.
Quick Answers
Figures below use Montana averages; energy prices as of October 2026.
Does a heat pump heat for less than natural gas in Montana?
No, natural gas still wins in Montana: 97,881 BTUs per dollar against 57,997 for a heat pump at COP 3. The break-even power price is about 10.5¢ per kWh, and the Montana average is 17.7¢. A more efficient heat pump narrows the gap.
Is electricity in Montana expensive compared with other states?
Montana pays 17.7¢ per kWh on average: 19% under the national figure of 21.7¢ and the 16th cheapest of 51. Cooling bills rise and fall with it.
Is a cold-climate heat pump needed in Montana?
Yes, plan on one. Winter lows in Montana average about 11°F statewide, where a standard heat pump loses much of its output. Cold-climate models keep heating below zero; size for the coldest nights.
What does a heat pump save over electric baseboard in Montana?
About two-thirds. At 17.7¢ per kWh (the Montana average), a million BTU of heat costs about $51.73 from baseboards and about $17.24 from a heat pump running at COP 3.
What is the best season to replace an AC or furnace in Montana?
Spring or fall, while the old system still runs. Winter lows near 11°F statewide mean heating work should wrap up by early fall. The first heat wave and the first cold snap fill every installer's calendar; replacing on your own schedule leaves room to compare quotes.
Is it smart to replace the furnace and AC together?
When both are aging, generally yes: one visit, one labor charge, and a matched coil and condenser, which the efficiency rating assumes. If one is fairly new, price each job on its own.
Check it for your own home: Central AC cost estimator or Heat pump cost calculator.
More HVAC Cost Guides
Montana HVAC costs (statewide) · HVAC costs in every state
