The formula
For each line item we multiply a quantity by a national unit cost, then apply a quality-grade factor. A regional labor multiplier is applied to the labor portion only; materials are priced nationally. We show the itemized result as a ±22% range.
National unit costs
| Line item | National unit cost | Source |
|---|---|---|
| Outdoor condenser unit | $1,200.00 / sq ft | source |
| Furnace / heating unit | $2,200.00 / sq ft | source |
| Evaporator coil / air handler | $1,500.00 / sq ft | source |
| Refrigerant lineset & connections | $700.00 / sq ft | source |
| Ductless mini-split (outdoor + heads) | $1,800.00 / sq ft | source |
| Ductwork replacement | $4.00 / sq ft | source |
| Installation labor | $900.00 / sq ft | source |
| Permit, disposal & startup | $800.00 / sq ft | source |
Regional labor multipliers
Each state's labor multiplier is its mean construction-trades wage relative to the national mean. The intended series is the U.S. Bureau of Labor Statistics Occupational Employment & Wage Statistics for HVAC mechanics (SOC 49-9021); because that all-state table could not be retrieved at build time, these figures use the cited BLS Carpenters series (SOC 47-2031) as a disclosed proxy pending verification. Multipliers are bounded to a sane range and applied to the labor share of each line item, so materials stay nationally priced while labor tracks local wages.
Data vintage and limitations
Compiled June 2026 from public cost aggregators and government wage data. These are derived estimates, not live contractor quotes. Local prices vary with project complexity, access, and material availability; always confirm with a licensed contractor before budgeting.
Sources
- https://homeguide.com/costs/hvac-cost
- https://taxfoundation.org/data/all/state/sales-tax-rates-midyear-2025/
- https://www.angi.com/articles/insider-s-price-guide-new-heating-and-cooling-system.htm
- https://www.bls.gov/ooh/construction-and-extraction/carpenters.htm
- https://www.carrier.com/residential/en/us/products/heating-cooling/hvac-replacement-cost/