Home / By tonnage / 3.5 ton
3.5-ton heat pump & AC cost
A 3.5-ton system moves 42,000 BTU per hour. Below: what 3.5-ton equipment lists for online today, and what a DOE national-lab benchmark says it should cost installed.
Installed-cost benchmark by system type and efficiency
REMDB (National Laboratory of the Rockies, formerly NREL) replacement-cost regressions, restated from 2023 dollars with CPI-U. National averages: high-cost metros run above them. Ductwork, permits beyond the norm and panel work are not included. Method
| System type | Standard | Mid-tier inverter | High-efficiency / cold-climate | Listed equipment |
|---|---|---|---|---|
| Central heat pump (ducted split) | $15,980 $8,985–$22,976 | $17,975 $10,182–$25,768 | $20,277 $11,563–$28,990 | — |
| Mini-split heat pump | $19,899 $11,939–$27,859 | $20,327 $12,196–$28,458 | $20,948 $12,569–$29,327 | — |
| Central AC + gas furnace | $11,522 $8,207–$15,371 | $13,108 $9,158–$17,591 | $15,409 $10,539–$20,813 | $6,205 |
| Heat pump only (outdoor unit swap) | $6,670 $3,812–$10,672 | $6,670 $3,812–$10,672 | $6,670 $3,812–$10,672 | — |
"Heat pump only" assumes the outdoor unit alone is replaced; its range is anchored on listed condenser prices, not REMDB, and is an estimate. AC + furnace assumes an 80,000 BTU/h, 80% AFUE furnace.
3.5-ton systems with listed prices
| System | Type | Tons | SEER2 | HSPF2 | Rating source | Lowest listed | Retailer |
|---|---|---|---|---|---|---|---|
| Goodman GLXS5BA4210 | AC + furnace | 3.5 | 15.2 | — | listing | $6,205 | HVACDirect |
Is 3.5 tons the right size?
Tonnage should come from a room-by-room load calculation (ACCA Manual J), not from square footage alone. Insulation, windows, air leakage, ceiling height and climate can move the answer by a ton or more. An oversized system short-cycles, dehumidifies poorly and costs more up front; an undersized one runs constantly on design days.
If your contractor matched the old unit's size without a load calculation, ask for one. If two contractors quote different tonnages for the same house, ask both to show their Manual J.
The weekly Quote Red-Flag Report
One email a week for homeowners: which rebates are actually open, real quotes we've graded (anonymized), and the upsell tricks to watch for. Free, no spam, unsubscribe anytime.