How much does it cost to replace ductwork?
Replacing ductwork costs $1,400 to $5,600 according to HomeGuide and $452 to $2,182 according to Angi, a gap in how they count linear feet.
The disagreement is worth understanding rather than averaging away. HomeGuide prices duct replacement at $25 to $55 per linear foot and says the average home has 100 linear feet of ductwork. Angi prices it at $10 to $25 per linear foot and says most residential homes have between 150 and 350. Different price per foot, different number of feet — which is how one guide lands on a national average of $3,500 and the other on $1,251.
This page is general information, not professional advice. Prices move with your equipment, your region and the season, and the only number that counts is a written quote from a licensed HVAC contractor who has looked at your system.
Air duct replacement cost by house size
Both guides publish a table by square footage, and putting them next to each other is more useful than picking one. Find your house on both rows and treat the two numbers as the edges of what you should expect to be quoted.
| Home size | HomeGuide | Angi | Angi's assumed duct run |
|---|---|---|---|
| 1,000 – 1,500 sq ft | $1,400 – $3,400 | $1,200 – $2,500 | 150 linear feet |
| 1,500 – 2,000 sq ft | $2,100 – $4,500 | $1,600 – $3,500 | 200 linear feet |
| 2,000 – 2,500 sq ft | $2,800 – $5,600 | $2,000 – $4,500 | 250 linear feet |
| 2,500 – 3,000 sq ft | $3,500 – $6,700 | $2,500 – $5,500 | 300 linear feet |
| 3,000 – 3,500 sq ft | $4,200 – $7,800 | $3,000 – $7,000 | 350 linear feet |
Notice that the two tables are far closer than the two headline averages. That is the practical takeaway: once you anchor on square footage instead of a national average, the guides mostly agree.
Cost to replace HVAC ducts by where they run
Access decides a lot of this. HomeGuide publishes the job by location: $3,000 to $7,300 in a crawl space, $2,200 to $5,600 in an attic, $1,800 to $3,100 in a basement, and $1,000 to $3,300 in a mobile home. It calls basement work the cheapest because the ducts are easy to reach, and notes that crawl space contractors often recommend cleaning, repairing or encapsulating the space before new ducts go in.
Source: HomeGuide
HomeGuide also prices the alternatives to a full replacement. A duct inspection for a replacement quote costs $40 to $100. Per duct run rather than per foot, replacement is $270 to $500. Ductwork tends to last 10 to 20 years and installing new ducts takes 1 to 2 days.
Source: HomeGuide
Why leaky ducts cost you twice
ENERGY STAR puts the scale of it plainly: in a typical house, about 20 to 30 percent of the air moving through the duct system is lost to leaks, holes and poorly connected ducts. That air is conditioned air you paid for, dumped into an attic or a crawl space.
Source: ENERGY STAR
Which is why a duct conversation belongs in every system-replacement conversation. A brand-new condenser pushing cold air into a leaking attic run is an expensive way to cool an attic, and no efficiency rating on the equipment fixes it.
Sealing is the cheaper first move where the ducts are otherwise sound. HomeGuide prices minor duct sealing and repairs at $300 to $1,500, and says a full replacement is what you do when some or all of the ducts are beyond repair.
New ductwork versus replacing what is there
They are priced differently and the words get used loosely. HomeGuide gives replacement at $25 to $55 per linear foot and a retrofit into a house that never had ducts at $40 to $65 per foot, or $2,400 to $6,600 for the job. The retrofit costs more because the runs, boots and returns all have to be routed through a house that was not built for them.
Source: HomeGuide
How the ducts get sized is a question worth asking out loud. The Air Conditioning Contractors of America publishes Manual D, an ANSI-approved standard for residential duct design, alongside Manual J for the load calculation. A contractor who quotes a duct system without referencing either is working from a rule of thumb.
Ducts are excluded from every installed system price on this site, including here: what a central air conditioner replacement costs.
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Questions people ask next
- How much is air duct replacement per linear foot?
- HomeGuide publishes $25 to $55 per linear foot for residential replacement and Angi publishes $10 to $25. Measure your own runs before accepting either total, because the guides also disagree on how many feet a typical house has.
- How long does ductwork last?
- HomeGuide says 10 to 20 years on average. HomeGuide also prices a duct inspection at $40 to $100, which is the cheap way to find out where yours sits before you commit to anything.
- Should I replace ductwork when I replace the AC?
- Ask for the ducts to be tested either way. ENERGY STAR says about 20 to 30 percent of the air moving through a typical duct system is lost to leaks and holes, and HomeGuide prices minor sealing and repairs at $300 to $1,500 against a full replacement at $1,400 to $5,600.
- How long does it take to replace ductwork?
- HomeGuide says installing new ducts takes 1 to 2 days. Crawl space and attic work runs at the longer end because of the access, which is also why those two locations carry the highest published price bands.
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