AC Replacement Cost in Montana
Locally calibrated hire vs. DIY cost data for ac replacement projects in Montana. Cited sources, permit requirements, and a full build guide, free.
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HIRE A PRO
$4,200–$8,300
Fully installed, labor + materials
DIY COST
$2,400–$4,700
Materials + rentals, your labor free
Complex project, structural or code-critical work involved.
Government Data · Government Data · Submitted Quotes (n=0)
How we got these numbers
National benchmark costs from RSMeans, Angi, Fixr, and HomeGuide are adjusted for Montana using two federal datasets: the Bureau of Economic Analysis Regional Price Parity (RPP) index and the Bureau of Labor Statistics (BLS) Occupational Employment and Wage Statistics. Montana's RPP is 0.9 (national baseline = 100) and its BLS labor adjustment factor is 0.91. Higher RPP means goods and services cost more relative to the national average; the BLS factor scales contractor labor rates to local wage levels. We blend these two adjustments, weighted 40% RPP, 60% BLS labor, to produce the ranges shown above.
adjusted_cost = national_benchmark × (0.4 × RPP/100 + 0.6 × bls_labor_adj)
RPP(Montana) = 0.9 · BLS adj = 0.91
What's included
| Item | Qty | Unit Cost | Subtotal |
|---|---|---|---|
| AC condenser unit | 1 (about 3 ton) | $2,200 | $2,200 |
| Matched evaporator coil | 1 | $900 | $900 |
| Line set, pad, and fittings | 1 set | $400 | $400 |
| Refrigerant and labor | 1 job | $1,500 | $1,500 |
| Materials Total | $5,000 | ||
Tools you'll need
See the tools we'd buy →TOOLS YOU PROBABLY OWN
TOOLS TO RENT OR BUY
Manifold gauges and vacuum pump
Pro equipment, part of why this is hired out
Refrigerant recovery machine
Required by law to recover old refrigerant
Electrical and brazing tools
Build sequence
- 1
Size the new system to the home with a proper load calculation.
COMMON MISTAKE
Oversizing short-cycles the unit and leaves the house humid.
- 2
Recover the old refrigerant legally and remove the old equipment.
- 3
Set the new condenser and coil, then braze and connect the line set.
- 4
Pull a vacuum on the lines, then charge with the correct refrigerant.
- 5
Wire it, test the airflow and temperature split, and confirm it holds charge.
Permits and code requirements
PERMIT REQUIREMENTS
Permit rules for ac replacement vary by city and county in Montana. Most structural, electrical, plumbing, or mechanical work needs a permit and an inspection. Confirm with your local building department, or see the Montana guide for specifics.
PERMIT THRESHOLD
Varies by municipality
Disclaimer: Always verify permit requirements with your local building department before starting work. Requirements vary by municipality and are updated periodically.
Frequently asked questions
NEXT STEPS
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UPDATED JUNE 2026