Duct Sealing Explained
Aeroseal Duct Sealing: How It Works and Whether It's Worth It Pros, Cons and the Homes That Benefit Most
Aeroseal duct sealing closes leaks from inside the ductwork, reaching gaps no one can get to by hand. Here is how the process works, what affects the cost, where it falls short and how to tell whether your home is a good candidate.
What Aeroseal Duct Sealing Is
Aeroseal is an aerosol-based duct sealing method that grew out of research at Lawrence Berkeley National Laboratory. Instead of a technician crawling through the attic with mastic and foil tape, the duct system is pressurized and filled with a fog of fine sealant particles. As air escapes through a crack, the particles collect at the edges of the opening and build up until it closes.
The appeal is reach. Manual sealing only fixes the joints a person can see and touch. Aeroseal works on leaks buried behind drywall, inside chases and in tight corners of the attic, which is where many Florida duct systems leak the most. It is one of several tools within our broader duct cleaning, sealing and repair services.
Start With a Duct Leakage Test
The U.S. Department of Energy estimates that a typical home loses about 20 to 30 percent of the air moving through its ducts to leaks, holes and poor connections. That is an average; your own system could be far tighter or far worse. A duct leakage test tells you which.
The test seals off the registers, pressurizes the ducts with a calibrated fan and measures how much air escapes. The result gives you a baseline in cubic feet per minute. If leakage is modest, sealing a few accessible joints by hand may be all you need. If it is high, an aerosol method becomes more attractive. Either way, you are deciding based on a measurement rather than a sales pitch.
How an Aeroseal Job Runs
Baseline measurement
Registers are blocked with foam plugs and the system is pressurized to record starting leakage.
Equipment protection
The air handler, coil and blower are isolated so sealant cannot reach them.
Sealant injection
A machine blows atomized sealant into the ducts while holding them under pressure, so particles flow toward every leak.
Live monitoring
Software tracks leakage as it drops, so the technician can see when sealing has reached its limit.
Final report
Plugs come out, a final test runs and you receive before-and-after numbers.
Aeroseal Pros and Cons
| Strengths | Limitations |
|---|---|
| Seals leaks inside walls and ceilings that cannot be reached by hand | Cannot fix crushed, disconnected or collapsed duct sections |
| Measured results with before-and-after numbers | Openings larger than roughly 5/8 inch need physical repair first |
| Usually completed in a single day | Does not clean ducts or remove existing contamination |
| Can reduce attic air being drawn into the home | Adds little value if ducts are already tight |
| Can improve airflow to rooms starved by leaks | Ducts near the end of their life may be better replaced |
Aeroseal Cost and What Drives It
Price depends on the home rather than a flat rate. The main factors are:
- System size and register count. More branches and outlets mean more prep and plugging.
- Repairs needed first. Disconnected runs or torn flex duct have to be fixed before sealing can work.
- Access. Tight attics and hard-to-reach air handlers take longer to set up.
- Combined work. Pairing sealing with cleaning or partial duct replacement changes the scope.
Compare any quote against the alternatives: hand-sealing accessible joints, replacing badly deteriorated runs, or doing nothing. The leakage test result is what makes that comparison meaningful.
Is Aeroseal Worth It? Who Benefits Most
The strongest candidates are homes where the test shows high leakage spread through hard-to-reach sections, homes with a few rooms that never cool properly despite a healthy AC, and houses where dusty or humid attic air seems to find its way inside. If your power bill keeps climbing with no equipment fault, leaky ducts are worth ruling out; our guide to a high electric bill from the AC covers other causes, and an AC that won't cool the whole house explores uneven temperatures.
We are happy to measure your system and talk through sealing options honestly. Call (941) 417-4848 or start with duct services in Sarasota or Bradenton duct work.
Common Questions
Questions Readers Ask
Is Aeroseal safe for my family?
The sealant is applied only while the system is isolated and the house is being worked on, and it cures inside the ductwork. The equipment is protected during the process. Homeowners with chemical sensitivities can ask for the product's safety data before work starts and plan to be out during application. Once the job is finished, the sealant stays inside the duct walls at the leak points.
How long does Aeroseal duct sealing take?
Most homes are sealed in a single day. The injection itself typically takes a few hours, with setup, register plugging and before-and-after testing added on. Homes that need duct repairs first, or very large systems, take longer. Your technician can give you a better estimate after seeing the attic and the number of registers.
What is a duct leakage test and do I need one?
A duct leakage test pressurizes your ductwork with a calibrated fan and measures how much air escapes, giving a number you can compare before and after any sealing. It is the best way to know whether sealing is worth paying for. Without it, you are guessing. It is especially useful if some rooms run warm or your bills seem high for your home's size.
Does Aeroseal replace duct cleaning?
No. Sealing closes leaks; it does not remove dust, debris or growth already inside the ducts. If the ducts are dirty, they should be cleaned before any sealing work. Our guide to duct cleaning versus duct sealing explains when each one matters and when a home benefits from both.
How long does an Aeroseal seal last?
The sealant is designed to remain in place for the life of the ductwork under normal operating conditions. It does not protect against new damage, such as a duct crushed during attic work or a run disconnected by someone servicing other equipment. A follow-up leakage test after major attic work confirms the system is still tight.
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