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Ductwork

Ductwork Installation Cost Calculator

Installed-cost estimate for sealing, partial replace, full replace, or new ductwork installation. Adjusts by sqft, material, stories, and access difficulty.

Quick answer: seal + insulate $1,500–$3,500. Partial replace $3,200–$7,500. Full replace $6,500–$14,500. New install $8,000–$18,000. Aeroseal adds $1,500–$3,200.

HVAC ductwork in a home

Installed cost · 1800 sqft · full replace · California

$16,508

range $10,505 – $24,012

Why it matters

Per DOE / LBNL studies, typical residential ductwork leaks 25–40% of conditioned air into attics or crawl spaces. Sealing + insulating cuts heating/cooling bills 10–20% on its own. Properly sized and sealed ducts can mean a smaller heat pump (saving $1,500–$3,000 on equipment) and avoid panel upgrades.

Quote check

  • · Manual D duct design (not "we’ll match what was there").
  • · Static pressure target ≤0.5 inWC at design airflow.
  • · R-8 insulation on ducts in unconditioned space.
  • · Mastic + mesh sealing at every joint (not foil tape alone).
  • · Pre/post blower-door + duct-blaster verification, not just visual.
  • · Aeroseal Pre/Post report if used.
Heat pump pairing: if you’re getting a heat pump quote that includes "we’ll need to rework your ducts," this calculator gives an independent check on that line item. Heat pumps move 30–50% more CFM than gas furnaces, so undersized return ducts and trunk lines are a common problem in retrofits.
Cost simulatorMonte Carlo simulationSee the full range of likely installed costs — with the odds
Optimistic—10% chance under
Most likely—the single most-likely cost
Safer budget—90% chance under

Run a Monte Carlo of 10,000 possible outcomes to see the full distribution and the single most-likely installed cost.

Press Run simulation to roll 10,000 scenarios and watch the odds take shape.

  • ~18%Asbestos in existing duct tape or wrap (pre-1980 home)+$500–$3,000
  • PossibleFraming or soffit work to route new trunk lines+$500–$3,000

Surprise odds are approximate planning estimates, not measured rates; cost ranges are sourced where shown. How this works.

Each cost line is drawn from a triangular distribution and correlated by a shared market factor (~0.5); the most-likely value and range emerge from the simulation, not the band. A planning simulation, not a quote.

New to ductwork?

Ductwork is the metal/fiber/flex air-distribution network that carries conditioned air from your furnace, AC, or heat pump to each room. In a typical 1,800 sqft home there’s 200–400 linear feet of duct, sized per ACCA Manual D to deliver design airflow to each register at acceptable static pressure (≤0.5 inWC). Leakage is the big problem — DOE studies show 25-40% typical leakage in older systems, dumping conditioned air into attics. Sealing alone often pays back in 2-4 years.

Read the full guide

Frequently asked questions

How much does ductwork installation cost in 2026?

Seal + insulate existing ducts: $1,500–$3,500 (1,800 sqft home). Partial replace of failing sections: $3,200–$7,500. Full replace reusing existing chases: $6,500–$14,500. New install (no existing ducts): $8,000–$18,000. Aeroseal injection adds $1,500–$3,200 and seals leaks from inside without tearing into walls.

Flex, sheet metal, or duct board?

Flex duct (insulated, lined corrugated): cheapest, most installed today, 15–20 year lifespan. Sheet metal (galvanized rigid): premium, longest life (40+ years), best for trunk lines, harder to install. Fiberglass duct board (rigid insulated panels): middle option, integral insulation, prone to mold if it gets wet. Most installs use flex for branch lines and sheet metal for the main trunk.

How much do leaky ducts cost me?

DOE / LBNL studies put typical residential duct leakage at 25-40% of conditioned air lost to attics/crawls. That equals $400–$900/yr wasted on heating + cooling in a typical home. Sealing alone (no replacement) typically pays back in 2-4 years. ENERGY STAR Home Improvement programs target ≤8% leakage post-sealing.

Do I need new ducts for a heat pump?

Often yes, partially. Heat pumps move 30-50% more CFM than gas furnaces at the same heating capacity (lower supply temperature means more airflow needed). Existing trunk lines and returns sized for a gas furnace are usually undersized for the heat pump replacement. A Manual D analysis is required to verify. Common upgrades: larger return ducts, balancing dampers, additional supply registers.

Is Aeroseal worth it?

Aeroseal is a polymer aerosol injected into the duct system that finds and seals leaks from inside. The process was developed at Lawrence Berkeley National Laboratory, whose field studies measured 60-90% leakage reduction (https://www.osti.gov/biblio/834673). Good fit for finished homes where exposing ducts is destructive (drywalled chases). Less compelling on open ducts where manual mastic sealing is easier and cheaper. $1,500–$3,200 typical add-on; payback 3-6 years in heating + cooling savings.

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