Duct replacement typically costs between $1,500 and $5,000 for an average home, depending on the size of your system, the materials used, and how accessible your ducts are

The price varies widely because duct work is custom to each house. A small ranch home with ducts in an attic might cost less than a two-story house where ducts run through walls and crawl spaces. Labor makes up most of the bill — removing old ducts, running new ones, sealing joints, and testing the system takes time. Materials (sheet metal, fiberglass, or flexible duct) are a smaller part of the total.

Most homeowners pay by the linear foot of duct installed, which usually runs $15 to $30 per foot for labor and materials combined. A typical home needs 300 to 500 feet of ductwork, which explains why the range is so broad. If your ducts are in an straightforward-to-reach attic, the job costs less. If they're buried in walls or require extensive framing, the price climbs.

Key Takeaways

  • Duct replacement costs $1,500 to $5,000 for most homes, with labor making up 60 to 70 percent of the bill.
  • The price per linear foot ranges from $15 to $30 depending on materials and how hard the ducts are to reach.
  • A full system replacement usually takes three to five days and requires your HVAC system to be shut down during installation.
  • Getting quotes from at least two licensed HVAC contractors helps you understand what's typical in your area.

What drives the cost up or down

The size of your home is the biggest factor. A 1,500-square-foot house needs less ductwork than a 3,000-square-foot one, and the difference shows in the bill. A contractor measures the square footage and calculates how much duct is needed, then quotes based on that.

Where the ducts run matters just as much. Ducts in an attic or basement are cheaper to replace because the contractor can access them without cutting into walls. Ducts hidden inside walls, under floors, or in tight crawl spaces require more labor — sometimes cutting and patching drywall or flooring, which adds $500 to $1,500 or more to the job.

The material you choose affects price too. Flexible duct (plastic-lined fabric) is the cheapest option and works well in most homes. Sheet metal ducts last longer and resist damage better, but cost more. Fiberglass-lined ducts offer insulation but are harder to clean and less common in new work.

When you might need duct replacement

Ducts typically last 15 to 20 years. If yours are older and you're seeing signs of failure — rooms that won't heat or cool evenly, visible damage, mold growth, or a spike in energy bills — replacement might be the right move. Patching old ducts is cheaper short-term but often fails within a few years.

If you're replacing your furnace or air conditioner anyway, replacing ducts at the same time can save money because the HVAC system is already shut down and the contractor is already on site. Some contractors bundle the work and offer a discount.

Duct sealing (closing gaps and leaks with mastic or tape) is much cheaper — usually $300 to $1,000 — and solves many problems without full replacement. A contractor can use a blower door test to find leaks and tell you whether sealing is enough or whether you need new ducts.

Getting accurate quotes

Call three licensed HVAC contractors and ask each one to visit your home and measure the ductwork. A quote over the phone is almost always wrong because the contractor can't see how your ducts are routed or what condition they're in. A site visit takes 30 minutes to an hour and should be free.

When you get quotes, ask what's included: removal of old ducts, new materials, labor, testing, and cleanup. Some contractors charge extra for disposal or for patching walls after they remove old ductwork. A detailed quote tells you what you're paying for.

Check that the contractor is licensed in your state and carries liability insurance. Ask for references from recent jobs — ideally homes similar in size to yours. The cheapest quote isn't always the best; a contractor who rushes the job or uses poor materials will cost you more in repairs later.

Timeline and what to expect

A full duct replacement usually takes three to five days, depending on how much ductwork needs to be replaced and how accessible it is. Your HVAC system will be off during most of the work, so plan for a few days without heating or cooling. In mild weather this is manageable; in winter or summer, it's uncomfortable.

The contractor will remove old ducts, install new ones, seal all joints with mastic (a putty-like sealant), and test the system for leaks using a blower door or smoke test. They'll also balance the system — adjusting dampers so air flows evenly to each room. This testing and balancing step is important and shouldn't be skipped.

After the work is done, ask the contractor for a report showing where ducts were sealed and what the final test results were. This documentation is useful if you sell the house or need warranty work later.

Alternatives to full replacement

If the cost is too high right now, duct sealing is a practical middle step. A contractor applies mastic sealant to leaking joints and can reduce energy loss by 10 to 20 percent. This costs $300 to $1,000 and buys you time before a full replacement becomes necessary.

Duct insulation (wrapping ducts with fiberglass or foam) can also help if your ducts run through unconditioned spaces like attics or crawl spaces. This prevents heat loss in winter and heat gain in summer, improving efficiency without replacing the ducts themselves. Insulation alone costs $200 to $600.

If only part of your ductwork is damaged — say, one section in a wall — some contractors will replace just that section rather than the whole system. This is cheaper but only works if the rest of the ducts are in good condition. Ask your contractor whether a partial replacement makes sense for your situation.

Frequently Asked Questions

Can I replace ducts myself to save money?

Ductwork requires precise measurement, proper sealing, and balancing to work correctly. A DIY job often results in leaks, poor airflow, and wasted energy. Hire a licensed contractor; the labor cost is worth the difference in performance and durability.

Does homeowners insurance cover duct replacement?

Standard homeowners insurance does not cover duct replacement unless the damage is from a covered event like a fire or severe storm. Wear and tear is your responsibility. Check your policy or ask your agent to be sure.

How long do new ducts last?

New sheet metal ducts last 20 to 30 years with proper maintenance. Flexible ducts typically last 15 to 20 years. Lifespan depends on how well the system is sealed, whether it's insulated, and how often it's cleaned.

What's the difference between sealing and replacing ducts?

Sealing closes leaks in existing ducts and costs $300 to $1,000. Replacement removes old ducts and installs new ones, costing $1,500 to $5,000. Sealing works if ducts are structurally sound; replacement is necessary if ducts are damaged, corroded, or too old to seal effectively.

Will new ducts lower my energy bills?

New, properly sealed ducts reduce energy loss and can lower heating and cooling costs by 10 to 30 percent, depending on how leaky the old system was. The savings depend on your climate, how much you run your HVAC system, and your local energy rates.