How Much Does Ductwork Insulation Cost? 2025 [Data]

Ductwork Insulation Cost by Material

One of the biggest cost factors when insulating your HVAC system is the type of insulation you choose to use. Insulation comes in many forms, and the cost of each type of insulation can vary based on its thickness and the material from which it’s made.

The basic types most commonly used to insulate air ducts include the following:

Fiberglass

Fiberglass duct insulation costs $1 to $4 per square foot, making it the most affordable option. It’s known for its easy installation and flexibility, and its energy efficiency can also lower bills.

Reflective Coil

Reflective coil duct insulation costs $4 to $8 per square foot. It works by using reflective surfaces to reduce heat loss and boost your HVAC’s efficiency. It’s often installed outside of the ducts using spacers to create air space.

Spray Foam Insulation

Spray foam insulation costs $8 to $13 per square foot. This material is sprayed into open cracks, gaps, and crevices, then expands up to 100 times its original size to seal those cavities against air leaks. It also won’t sag or lose shape over time. 

Duct Board Insulation

Foam or duct board insulation costs $6 to $10 per square foot. Often applied to the exterior of HVAC ducts, these 1-, 1 ½-, or 2-inch thick boards are made from either fiberglass or mineral wool with an outer aluminum layer to seal out air and moisture.

Ductwork Insulation Cost by R-Value

The IECC has specific insulation requirements for ducts. Attic ducts larger than three inches in diameter, for example, must have a minimum thickness of R-8, while all ducts smaller than three inches must maintain a minimum thickness of R-6. For ducts less than 3 inches, the insulation thickness should be at least R-4.2. It's worth noting that thicker insulation enhances temperature retention and reduces noise. However, it's important to remember that higher R-values come with a higher price tag.

Cost of Ductwork Insulation by Location

The cost to insulate your HVAC system’s ductwork will vary depending on the labor cost in your local area. Below is a list of the typical price range for ductwork insulation in several major cities throughout the U.S.

Insulating Ductwork Yourself vs. Hiring a Pro

Ductwork insulation tends to be a messy and labor-intensive project that involves accessing hard-to-reach areas of your home. Removing and reattaching any sections of ductwork may be necessary to complete the task. However, in most municipalities, only licensed HVAC technicians are allowed to do the work.

We recommend consulting with a professional insulation contractor in your area or a local duct installer to get an estimate instead of doing the project yourself.

Cost of Common Ductwork Add-Ons

While a technician is on-site insulating your home's ductwork, it's also a good time to consider having them tackle other HVAC-related tasks on your to-do list.

• Duct sealing cost: $500 – $4,000

• Duct cleaning cost: $270 – $500

• Rerouting ducts cost: $1,500 – $9,000

How Angi Gets Its Cost Data

Home is the most important place on earth, which is why Angi has helped more than 150 million homeowners transform their houses into homes they adore. To help homeowners with their next project, Angi provides readers with the most accurate cost data and upholds strict editorial standards. We extensively research project costs to develop the pricing data you see, so you can make the best decisions for you and your home. We rely on reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects. 

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